DB code: S00512

RLCP classification 1.13.30000.16 : Hydrolysis
CATH domain 3.40.710.10 : Beta-lactamase Catalytic domain
E.C. 3.5.2.6
CSA 2blt
M-CSA 2blt
MACiE

CATH domain Related DB codes (homologues)
3.40.710.10 : Beta-lactamase S00513 S00529 S00414 T00222

Uniprot Enzyme Name
UniprotKB Protein name Synonyms MEROPS Pfam RefSeq
P05364 Beta-lactamase
EC 3.5.2.6
Cephalosporinase
S12.006 (Serine)
PF00144 (Beta-lactamase)
[Graphical View]
P00811 Beta-lactamase
EC 3.5.2.6
Cephalosporinase
S12.006 (Serine)
PF00144 (Beta-lactamase)
[Graphical View]
NP_418574.1 (Protein)
NC_000913.2 (DNA/RNA sequence)
YP_492295.1 (Protein)
NC_007779.1 (DNA/RNA sequence)
Q46041
Beta-lactamase
PF00144 (Beta-lactamase)
[Graphical View]

KEGG enzyme name
beta-lactamase
penicillinase
cephalosporinase
neutrapen
penicillin beta-lactamase
exopenicillinase
ampicillinase
penicillin amido-beta-lactamhydrolase
penicillinase I, II
beta-lactamase I-III
beta-lactamase A, B, C
beta-lactamase AME I
cephalosporin-beta-lactamase

UniprotKB: Accession Number Entry name Activity Subunit Subcellular location Cofactor
P05364 AMPC_ENTCL A beta-lactam + H(2)O = a substituted beta- amino acid. Periplasm (By similarity).
P00811 AMPC_ECOLI A beta-lactam + H(2)O = a substituted beta- amino acid. Monomer. Periplasm.
Q46041 Q46041_CITFR

KEGG Pathways
Map code Pathways E.C.
MAP00311 Penicillin and cephalosporin biosynthesis
MAP00312 beta-Lactam resistance

Compound table
Substrates Products Intermediates
KEGG-id C01866 C00395 C00875 C00001 C03806
E.C.
Compound beta-Lactam Penicillin Cephalosporin H2O Substituted beta-amino acid
Type amide group amide group,carboxyl group,sulfide group amide group,amine group,carboxyl group,sulfide group H2O amino acids
ChEBI 15377
PubChem 22247451
962
1blsA Pdbj logo s Rasmollogo id Rasmollogo chain Mmcif id Mmcif chain Unbound Unbound Unbound Unbound Transition-state-analogue:IPP
1blsB Pdbj logo s Rasmollogo id Rasmollogo chain Mmcif id Mmcif chain Unbound Unbound Unbound Unbound Transition-state-analogue:IPP
1gceA Pdbj logo s Rasmollogo id Rasmollogo chain Mmcif id Mmcif chain Unbound Unbound Unbound Unbound Unbound
1c3bA Pdbj logo s Rasmollogo id Rasmollogo chain Mmcif id Mmcif chain Unbound Unbound Unbound Unbound Transition-state-analogue:BZB
1c3bB Pdbj logo s Rasmollogo id Rasmollogo chain Mmcif id Mmcif chain Unbound Unbound Unbound Unbound Transition-state-analogue:BZB
1fcmA Pdbj logo s Rasmollogo id Rasmollogo chain Mmcif id Mmcif chain Unbound Unbound Unbound Unbound Intermediate-analogue:CXN
1fcmB Pdbj logo s Rasmollogo id Rasmollogo chain Mmcif id Mmcif chain Unbound Unbound Unbound Unbound Intermediate-analogue:CXN
1fcnA Pdbj logo s Rasmollogo id Rasmollogo chain Mmcif id Mmcif chain Unbound Unbound Unbound Unbound Intermediate-analogue:LOR
1fcnB Pdbj logo s Rasmollogo id Rasmollogo chain Mmcif id Mmcif chain Unbound Unbound Unbound Unbound Intermediate-analogue:LOR
1fcoA Pdbj logo s Rasmollogo id Rasmollogo chain Mmcif id Mmcif chain Unbound Unbound Unbound Unbound Intermediate-analogue:MOX
1fcoB Pdbj logo s Rasmollogo id Rasmollogo chain Mmcif id Mmcif chain Unbound Unbound Unbound Unbound Intermediate-analogue:MOX
1fswA Pdbj logo s Rasmollogo id Rasmollogo chain Mmcif id Mmcif chain Unbound Unbound Unbound Unbound Transition-state-analogue:CTB
1fswB Pdbj logo s Rasmollogo id Rasmollogo chain Mmcif id Mmcif chain Unbound Unbound Unbound Unbound Transition-state-analogue:CTB
1fsyA Pdbj logo s Rasmollogo id Rasmollogo chain Mmcif id Mmcif chain Unbound Unbound Unbound Unbound Transition-state-analogue:105
1fsyB Pdbj logo s Rasmollogo id Rasmollogo chain Mmcif id Mmcif chain Unbound Unbound Unbound Unbound Transition-state-analogue:105
2blsA Pdbj logo s Rasmollogo id Rasmollogo chain Mmcif id Mmcif chain Unbound Unbound Unbound Unbound Unbound
2blsB Pdbj logo s Rasmollogo id Rasmollogo chain Mmcif id Mmcif chain Unbound Unbound Unbound Unbound Unbound
2bltA Pdbj logo s Rasmollogo id Rasmollogo chain Mmcif id Mmcif chain Unbound Unbound Unbound Unbound Unbound
2bltB Pdbj logo s Rasmollogo id Rasmollogo chain Mmcif id Mmcif chain Unbound Unbound Unbound Unbound Unbound
3blsA Pdbj logo s Rasmollogo id Rasmollogo chain Mmcif id Mmcif chain Unbound Unbound Unbound Unbound Transition-state-analogue:APB
3blsB Pdbj logo s Rasmollogo id Rasmollogo chain Mmcif id Mmcif chain Unbound Unbound Unbound Unbound Transition-state-analogue:APB
1fr1A Pdbj logo s Rasmollogo id Rasmollogo chain Mmcif id Mmcif chain Unbound Unbound Unbound Unbound Unbound
1fr1B Pdbj logo s Rasmollogo id Rasmollogo chain Mmcif id Mmcif chain Unbound Unbound Unbound Unbound Unbound
1fr6A Pdbj logo s Rasmollogo id Rasmollogo chain Mmcif id Mmcif chain Unbound Unbound Unbound Unbound Intermediate-analogue:AZR
1fr6B Pdbj logo s Rasmollogo id Rasmollogo chain Mmcif id Mmcif chain Unbound Unbound Unbound Unbound Intermediate-analogue:AZR

Reference for Active-site residues
resource references E.C.

Active-site residues
PDB Catalytic residues Cofactor-binding residues Modified residues Main-chain involved in catalysis Comment
1blsA Pdbj logo s Rasmollogo id Rasmollogo chain Mmcif id Mmcif chain SER 64;LYS 67;TYR 150;LYS 315;THR 316 SER 64;SER 318
1blsB Pdbj logo s Rasmollogo id Rasmollogo chain Mmcif id Mmcif chain SER 64;LYS 67;TYR 150;LYS 315;THR 316 SER 64;SER 318
1gceA Pdbj logo s Rasmollogo id Rasmollogo chain Mmcif id Mmcif chain SER 64;LYS 67;TYR 150;LYS 318;THR 319 SER 64;SER 321
1c3bA Pdbj logo s Rasmollogo id Rasmollogo chain Mmcif id Mmcif chain SER 64;LYS 67;TYR 150;LYS 315;THR 316 SER 64;ALA 318
1c3bB Pdbj logo s Rasmollogo id Rasmollogo chain Mmcif id Mmcif chain SER 64;LYS 67;TYR 150;LYS 315;THR 316 SER 64;ALA 318
1fcmA Pdbj logo s Rasmollogo id Rasmollogo chain Mmcif id Mmcif chain SER 61;LYS 64; ;LYS 312;THR 313 SER 61;ALA 315 mutant Q117L, Y147E
1fcmB Pdbj logo s Rasmollogo id Rasmollogo chain Mmcif id Mmcif chain SER 61;LYS 64; ;LYS 312;THR 313 SER 61;ALA 315 mutant Q117L, Y147E
1fcnA Pdbj logo s Rasmollogo id Rasmollogo chain Mmcif id Mmcif chain SER 61;LYS 64; ;LYS 312;THR 313 SER 61;ALA 315 mutant Q117L, Y147E
1fcnB Pdbj logo s Rasmollogo id Rasmollogo chain Mmcif id Mmcif chain SER 61;LYS 64; ;LYS 312;THR 313 SER 61;ALA 315 mutant Q117L, Y147E
1fcoA Pdbj logo s Rasmollogo id Rasmollogo chain Mmcif id Mmcif chain SER 61;LYS 64;TYR 147;LYS 312;THR 313 SER 61;ALA 315
1fcoB Pdbj logo s Rasmollogo id Rasmollogo chain Mmcif id Mmcif chain SER 61;LYS 64;TYR 147;LYS 312;THR 313 SER 61;ALA 315
1fswA Pdbj logo s Rasmollogo id Rasmollogo chain Mmcif id Mmcif chain SER 64;LYS 67;TYR 150;LYS 315;THR 316 SER 64;ALA 318
1fswB Pdbj logo s Rasmollogo id Rasmollogo chain Mmcif id Mmcif chain SER 64;LYS 67;TYR 150;LYS 315;THR 316 SER 64;ALA 318
1fsyA Pdbj logo s Rasmollogo id Rasmollogo chain Mmcif id Mmcif chain SER 64;LYS 67;TYR 150;LYS 315;THR 316 SER 64;ALA 318
1fsyB Pdbj logo s Rasmollogo id Rasmollogo chain Mmcif id Mmcif chain SER 64;LYS 67;TYR 150;LYS 315;THR 316 SER 64;ALA 318
2blsA Pdbj logo s Rasmollogo id Rasmollogo chain Mmcif id Mmcif chain SER 64;LYS 67;TYR 150;LYS 315;THR 316 SER 64;ALA 318
2blsB Pdbj logo s Rasmollogo id Rasmollogo chain Mmcif id Mmcif chain SER 64;LYS 67;TYR 150;LYS 315;THR 316 SER 64;ALA 318
2bltA Pdbj logo s Rasmollogo id Rasmollogo chain Mmcif id Mmcif chain SER 64;LYS 67;TYR 150;LYS 315;THR 316 SER 64;SER 318
2bltB Pdbj logo s Rasmollogo id Rasmollogo chain Mmcif id Mmcif chain SER 64;LYS 67;TYR 150;LYS 315;THR 316 SER 64;SER 318
3blsA Pdbj logo s Rasmollogo id Rasmollogo chain Mmcif id Mmcif chain SER 64;LYS 67;TYR 150;LYS 315;THR 316 SER 64;ALA 318
3blsB Pdbj logo s Rasmollogo id Rasmollogo chain Mmcif id Mmcif chain SER 64;LYS 67;TYR 150;LYS 315;THR 316 SER 64;ALA 318
1fr1A Pdbj logo s Rasmollogo id Rasmollogo chain Mmcif id Mmcif chain SER 64;LYS 67;TYR 150;LYS 315;THR 316 SER 64;SER 318
1fr1B Pdbj logo s Rasmollogo id Rasmollogo chain Mmcif id Mmcif chain SER 64;LYS 67;TYR 150;LYS 315;THR 316 SER 64;SER 318
1fr6A Pdbj logo s Rasmollogo id Rasmollogo chain Mmcif id Mmcif chain SER 64;LYS 67;TYR 150;LYS 315;THR 316 SER 64;SER 318
1fr6B Pdbj logo s Rasmollogo id Rasmollogo chain Mmcif id Mmcif chain SER 64;LYS 67;TYR 150;LYS 315;THR 316 SER 64;SER 318

References for Catalytic Mechanism
References Sections No. of steps in catalysis
[1]
Fig.3 3
[2]
p.11261
[4]
p.6767-6771
[5]
Fig.7, p.8584-8586 2
[11]
p.2334-2336
[12]
Fig.1, p.10511-10512
[14]
Fig.2 2
[15]
p.4619-4620
[17]
p.6238-6239
[22]
Fig.1(A), Fig.5, p.418-419, p.421 2
[26]
p.180
[29]
p.1768-1769

References
[1]
Resource
Comments X-ray crystallography (2.0 Angstroms)
Medline ID
PubMed ID 2300174
Journal Nature
Year 1990
Volume 343
Pages 284-8
Authors Oefner C, D'Arcy A, Daly JJ, Gubernator K, Charnas RL, Heinze I, Hubschwerlen C, Winkler FK
Title Refined crystal structure of beta-lactamase from Citrobacter freundii indicates a mechanism for beta-lactam hydrolysis.
Related PDB 1fr1 1fr6
Related UniProtKB
[2]
Resource
Comments X-ray crystallography (2 Angstroms)
Medline ID 94068583
PubMed ID 8248237
Journal Proc Natl Acad Sci U S A
Year 1993
Volume 90
Pages 11257-61
Authors Lobkovsky E, Moews PC, Liu H, Zhao H, Frere JM, Knox JR
Title Evolution of an enzyme activity: crystallographic structure at 2-A resolution of cephalosporinase from the ampC gene of Enterobacter cloacae P99 and comparison with a class A penicillinase.
Related PDB 2blt
Related UniProtKB P05364
[3]
Resource
Comments
Medline ID
PubMed ID 8172894
Journal Biochemistry
Year 1994
Volume 33
Pages 5193-201
Authors Monnaie D, Dubus A, Cooke D, Marchand-Brynaert J, Normark S, Frere JM
Title Role of residue Lys315 in the mechanism of action of the Enterobacter cloacae 908R beta-lactamase.
Related PDB
Related UniProtKB
[4]
Resource
Comments X-ray crystallography (2.3 Angstroms)
Medline ID 94263990
PubMed ID 8204611
Journal Biochemistry
Year 1994
Volume 33
Pages 6762-72
Authors Lobkovsky E, Billings EM, Moews PC, Rahil J, Pratt RF, Knox JR
Title Crystallographic structure of a phosphonate derivative of the Enterobacter cloacae P99 cephalosporinase: mechanistic interpretation of a beta-lactamase transition-state analog.
Related PDB 1bls
Related UniProtKB P05364
[5]
Resource
Comments
Medline ID
PubMed ID 8031792
Journal Biochemistry
Year 1994
Volume 33
Pages 8577-86
Authors Dubus A, Normark S, Kania M, Page MG
Title The role of tyrosine 150 in catalysis of beta-lactam hydrolysis by AmpC beta-lactamase from Escherichia coli investigated by site-directed mutagenesis.
Related PDB
Related UniProtKB
[6]
Resource
Comments X-ray crystallography (2.0-2.3 Angstroms)
Medline ID 99036630
PubMed ID 9819201
Journal Biochemistry
Year 1998
Volume 37
Pages 16082-92
Authors Usher KC, Blaszczak LC, Weston GS, Shoichet BK, Remington SJ
Title Three-dimensional structure of AmpC beta-lactamase from Escherichia coli bound to a transition-state analogue: possible implications for the oxyanion hypothesis and for inhibitor design.
Related PDB 2bls
Related UniProtKB P00811
[7]
Resource
Comments
Medline ID
PubMed ID 9931012
Journal Biochemistry
Year 1999
Volume 38
Pages 1469-77
Authors Adediran SA, Pratt RF
Title Beta-secondary and solvent deuterium kinetic isotope effects on catalysis by the Streptomyces R61 DD-peptidase: comparisons with a structurally similar class C beta-lactamase.
Related PDB
Related UniProtKB
[8]
Resource
Comments
Medline ID
PubMed ID 10049265
Journal Antimicrob Agents Chemother
Year 1999
Volume 43
Pages 543-8
Authors Trepanier S, Knox JR, Clairoux N, Sanschagrin F, Levesque RC, Huletsky A
Title Structure-function studies of Ser-289 in the class C beta-lactamase from Enterobacter cloacae P99.
Related PDB
Related UniProtKB
[9]
Resource
Comments
Medline ID
PubMed ID 10393100
Journal Biochem J
Year 1999
Volume 341
Pages 409-13
Authors Rhazi N, Galleni M, Page MI, Frere JM
Title Peptidase activity of beta-lactamases.
Related PDB
Related UniProtKB
[10]
Resource
Comments X-ray crystallography (1.8 Angstroms)
Medline ID
PubMed ID 10441119
Journal Biochemistry
Year 1999
Volume 38
Pages 10256-61
Authors Crichlow GV, Kuzin AP, Nukaga M, Mayama K, Sawai T, Knox JR
Title Structure of the extended-spectrum class C beta-lactamase of Enterobacter cloacae GC1, a natural mutant with a tandem tripeptide insertion.
Related PDB 1gce
Related UniProtKB
[11]
Resource
Comments X-ray crystallography (2.25 Angstroms)
Medline ID 20060984
PubMed ID 10595535
Journal Protein Sci
Year 1999
Volume 8
Pages 2330-2337
Authors Powers RA, Blazquez J, Weston GS, Morosini MI, Baquero F, Shoichet BK
Title The complexed structure and antimicrobial activity of a non-beta-lactam inhibitor of AmpC beta-lactamase.
Related PDB 1c3b
Related UniProtKB P00811
[12]
Resource
Comments
Medline ID
PubMed ID
Journal J Am Chem Soc
Year 2000
Volume 122
Pages 10504-12
Authors Patera A, Blaszczak LC, Shoichet BK
Title Crystal structures of substrate and inhibitor complexes with ampc -lactamase: possible implications for substrate-assisted catalysis.
Related PDB 1fcm 1fcn 1fco
Related UniProtKB
[13]
Resource
Comments
Medline ID
PubMed ID 11134945
Journal Acta Crystallogr D Biol Crystallogr
Year 2001
Volume 57
Pages 162-4
Authors Wouters J, Charlier P, Monnaie D, Frere JM, Fonze E
Title Expression, purification, crystallization and preliminary X-ray analysis of the native class C beta-lactamase from Enterobacter cloacae 908R and two mutants.
Related PDB
Related UniProtKB
[14]
Resource
Comments X-ray crystallography (1.75/1.90 Angstroms)
Medline ID
PubMed ID 11182316
Journal Chem Biol
Year 2001
Volume 8
Pages 17-31
Authors Caselli E, Powers RA, Blasczcak LC, Wu CY, Prati F, Shoichet BK
Title Energetic, structural, and antimicrobial analyses of beta-lactam side chain recognition by beta-lactamases.
Related PDB 1fsw 1fsy
Related UniProtKB
[15]
Resource
Comments
Medline ID
PubMed ID 11294628
Journal Biochemistry
Year 2001
Volume 40
Pages 4610-21
Authors Kaur K, Pratt RF
Title Mechanism of reaction of acyl phosph(on)ates with the beta-lactamase of Enterobacter cloacae P99.
Related PDB
Related UniProtKB
[16]
Resource
Comments
Medline ID
PubMed ID 11300697
Journal Bioorg Chem
Year 2001
Volume 29
Pages 77-95
Authors Slater MJ, Laws AP, Page MI
Title The relative catalytic efficiency of beta-lactamase catalyzed acyl and phosphyl transfer.
Related PDB
Related UniProtKB
[17]
Resource
Comments
Medline ID
PubMed ID 11371184
Journal Biochemistry
Year 2001
Volume 40
Pages 6233-9
Authors Crichlow GV, Nukaga M, Doppalapudi VR, Buynak JD, Knox JR
Title Inhibition of class C beta-lactamases: structure of a reaction intermediate with a cephem sulfone.
Related PDB
Related UniProtKB
[18]
Resource
Comments
Medline ID
PubMed ID 11434768
Journal Biochemistry
Year 2001
Volume 40
Pages 7992-9
Authors Trehan I, Beadle BM, Shoichet BK
Title Inhibition of AmpC beta-lactamase through a destabilizing interaction in the active site.
Related PDB
Related UniProtKB
[19]
Resource
Comments
Medline ID
PubMed ID 11478888
Journal Biochemistry
Year 2001
Volume 40
Pages 9207-14
Authors Powers RA, Caselli E, Focia PJ, Prati F, Shoichet BK
Title Structures of ceftazidime and its transition-state analogue in complex with AmpC beta-lactamase: implications for resistance mutations and inhibitor design.
Related PDB
Related UniProtKB
[20]
Resource
Comments
Medline ID
PubMed ID 11709298
Journal Antimicrob Agents Chemother
Year 2001
Volume 45
Pages 3279-86
Authors Rudgers GW, Huang W, Palzkill T
Title Binding properties of a peptide derived from beta-lactamase inhibitory protein.
Related PDB
Related UniProtKB
[21]
Resource
Comments
Medline ID
PubMed ID 11914079
Journal Biochemistry
Year 2002
Volume 41
Pages 4329-38
Authors Bell JH, Pratt RF
Title Mechanism of inhibition of the beta-lactamase of Enterobacter cloacae P99 by 1:1 complexes of vanadate with hydroxamic acids.
Related PDB
Related UniProtKB
[22]
Resource
Comments
Medline ID
PubMed ID 12005439
Journal Structure (Camb)
Year 2002
Volume 10
Pages 413-24
Authors Beadle BM, Trehan I, Focia PJ, Shoichet BK
Title Structural milestones in the reaction pathway of an amide hydrolase: substrate, acyl, and product complexes of cephalothin with AmpC beta-lactamase.
Related PDB
Related UniProtKB
[23]
Resource
Comments
Medline ID
PubMed ID 12121656
Journal Structure (Camb)
Year 2002
Volume 10
Pages 1013-23
Authors Powers RA, Morandi F, Shoichet BK
Title Structure-based discovery of a novel, noncovalent inhibitor of AmpC beta-lactamase.
Related PDB
Related UniProtKB
[24]
Resource
Comments
Medline ID
PubMed ID 12435704
Journal Antimicrob Agents Chemother
Year 2002
Volume 46
Pages 3978-80
Authors Beadle BM, Shoichet BK
Title Structural basis for imipenem inhibition of class C beta-lactamases.
Related PDB
Related UniProtKB
[25]
Resource
Comments
Medline ID
PubMed ID 12482929
Journal Proc Natl Acad Sci U S A
Year 2002
Volume 99
Pages 16537-42
Authors Baker K, Bleczinski C, Lin H, Salazar-Jimenez G, Sengupta D, Krane S, Cornish VW
Title Chemical complementation: a reaction-independent genetic assay for enzyme catalysis.
Related PDB
Related UniProtKB
[26]
Resource
Comments
Medline ID
PubMed ID 12513696
Journal Biochem J
Year 2003
Volume 371
Pages 175-81
Authors Kato-Toma Y, Iwashita T, Masuda K, Oyama Y, Ishiguro M
Title pKa measurements from nuclear magnetic resonance of tyrosine-150 in class C beta-lactamase.
Related PDB
Related UniProtKB
[27]
Resource
Comments
Medline ID
PubMed ID 12696055
Journal Proteins
Year 2003
Volume 51
Pages 442-52
Authors Fenollar-Ferrer C, Frau J, Donoso J, Munoz F
Title Role of beta-lactam carboxyl group on binding of penicillins and cephalosporins to class C beta-lactamases.
Related PDB
Related UniProtKB
[28]
Resource
Comments
Medline ID
PubMed ID 12904027
Journal J Am Chem Soc
Year 2003
Volume 125
Pages 9612-8
Authors Meroueh SO, Minasov G, Lee W, Shoichet BK, Mobashery S
Title Structural aspects for evolution of beta-lactamases from penicillin-binding proteins.
Related PDB
Related UniProtKB
[29]
Resource
Comments
Medline ID
PubMed ID 14521155
Journal Cell Mol Life Sci
Year 2003
Volume 60
Pages 1764-73
Authors Wouters J, Fonze E, Vermeire M, Frere JM, Charlier P
Title Crystal structure of Enterobacter cloacae 908R class C beta-lactamase bound to iodo-acetamido-phenyl boronic acid, a transition-state analogue.
Related PDB
Related UniProtKB

Comments
This enzyme belongs to the class-C beta-lactamase family.
Ser64 acts as a nucleophile, making a nucleophilic attack on beta-lactam ring, to form acyl-enzyme intermediate.
According to the early studies ([1], [3], [4] & [5]), Tyr150 was considered to function as general acid-base.
In contrast, the more recent report, [22], suggested substrate-assisted base. In this reported mechanism, C4' carboxylate of the substrate may activate Tyr150, which in turn may activate Ser64 by abstracting a proton from the serine residue during the acylation step [22]. Lys67 might play an intermediary role in transfer of the proton [22].
In the next deacylation step, a water molecule bound to Thr316 (and possibly Tyr150) makes an attack on the C8 carbonyl carbon of the acyl-enzyme intermediate, activating the Ser64 to be a leaving group [22].
The role of Tyr150 seems to be still controversial. However, considering the structure with ligand, Ser64, Tyr150, and Lys150 act as a nucleophile, acid-base, and a modulator for acid-base. Here, mainchain amide groups of Ser64 and Ser318 form an oxyanion hole. These suggest that the mechanism is very similar to that of trypsin (D00197).

Created Updated
2002-09-27 2009-10-01