1bmc
From Proteopedia
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==Overview== | ==Overview== | ||
| - | The 3-D structure of Bacillus cereus (569/H/9) beta-lactamase (EC | + | The 3-D structure of Bacillus cereus (569/H/9) beta-lactamase (EC 3.5.2.6), which catalyses the hydrolysis of nearly all beta-lactams, has been solved at 2.5 A resolution by the multiple isomorphous replacement method, with density modification and phase combination, from crystals of the native protein and of a specially designed mutant (T97C). The current model includes 212 of the 227 amino acid residues, the zinc ion and 10 water molecules. The protein is folded into a beta beta sandwich with helices on each external face. To our knowledge, this fold has never been observed. An approximate internal molecular symmetry is found, with a 2-fold axis passing roughly through the zinc ion and suggesting a possible gene duplication. The active site is located at one edge of the beta beta sandwich and near the N-terminal end of a helix. The zinc ion is coordinated by three histidine residues (86, 88 and 149) and a water molecule. A sequence comparison of the relevant metallo-beta-lactamases, based on this protein structure, highlights a few well-conserved amino acid residues. The structure shows that most of these residues are in the active site. Among these, aspartic acid 90 and histidine 210 participate in a proposed catalytic mechanism for beta-lactam hydrolysis. |
==About this Structure== | ==About this Structure== | ||
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[[Category: signal]] | [[Category: signal]] | ||
| - | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 11:56:50 2008'' |
Revision as of 09:56, 21 February 2008
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STRUCTURE OF A ZINC METALLO-BETA-LACTAMASE FROM BACILLUS CEREUS
Overview
The 3-D structure of Bacillus cereus (569/H/9) beta-lactamase (EC 3.5.2.6), which catalyses the hydrolysis of nearly all beta-lactams, has been solved at 2.5 A resolution by the multiple isomorphous replacement method, with density modification and phase combination, from crystals of the native protein and of a specially designed mutant (T97C). The current model includes 212 of the 227 amino acid residues, the zinc ion and 10 water molecules. The protein is folded into a beta beta sandwich with helices on each external face. To our knowledge, this fold has never been observed. An approximate internal molecular symmetry is found, with a 2-fold axis passing roughly through the zinc ion and suggesting a possible gene duplication. The active site is located at one edge of the beta beta sandwich and near the N-terminal end of a helix. The zinc ion is coordinated by three histidine residues (86, 88 and 149) and a water molecule. A sequence comparison of the relevant metallo-beta-lactamases, based on this protein structure, highlights a few well-conserved amino acid residues. The structure shows that most of these residues are in the active site. Among these, aspartic acid 90 and histidine 210 participate in a proposed catalytic mechanism for beta-lactam hydrolysis.
About this Structure
1BMC is a Single protein structure of sequence from Bacillus cereus with as ligand. Active as Beta-lactamase, with EC number 3.5.2.6 Known structural/functional Site: . Full crystallographic information is available from OCA.
Reference
The 3-D structure of a zinc metallo-beta-lactamase from Bacillus cereus reveals a new type of protein fold., Carfi A, Pares S, Duee E, Galleni M, Duez C, Frere JM, Dideberg O, EMBO J. 1995 Oct 16;14(20):4914-21. PMID:7588620
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