2bmi: Difference between revisions
New page: left|200px<br /><applet load="2bmi" size="450" color="white" frame="true" align="right" spinBox="true" caption="2bmi, resolution 2.00Å" /> '''METALLO-BETA-LACTAMA... |
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[[Image:2bmi.jpg|left|200px]]<br /><applet load="2bmi" size=" | [[Image:2bmi.jpg|left|200px]]<br /><applet load="2bmi" size="350" color="white" frame="true" align="right" spinBox="true" | ||
caption="2bmi, resolution 2.00Å" /> | caption="2bmi, resolution 2.00Å" /> | ||
'''METALLO-BETA-LACTAMASE'''<br /> | '''METALLO-BETA-LACTAMASE'''<br /> | ||
==Overview== | ==Overview== | ||
beta-Lactamases are extracellular or periplasmic bacterial enzymes which | beta-Lactamases are extracellular or periplasmic bacterial enzymes which confer resistance to beta-lactam antibiotics. On the basis of their catalytic mechanisms, they can be divided into two major groups: active-site serine enzymes (classes A, C and D) and the ZnII enzymes (class B). The first crystal structure of a class B enzyme, the metallo-beta-lactamase from Bacillus cereus, has been solved at 2.5 A resolution [Carfi, Pares, Duee, Galleni, Duez, Frere & Dideberg (1995). EMBO J. 14, 4914-4921]. Recently, the crystal structure of the metallo-beta-lactamase from Bacteroides fragilis has been determined in a tetragonal space group [Concha, Rasmussen, Bush & Herzberg (1996). Structure, 4, 823-836]. The structure of the metallo-beta-lactamase from B. fragilis in an orthorhombic crystal form at 2.0 A resolution is reported here. The final crystallographic R is 0.196 for all the 32501 observed reflections in the range 10-2.0 A. The refined model includes 458 residues, 437 water molecules, four zinc and two sodium ions. These structures are discussed with reference to Zn binding and activity. A catalytic mechanism is proposed which is coherent with metallo-beta-lactamases being active with either one Zn ion (as in Aeromonas hydrophila) or two Zn ions (as in B. fragilis) bound to the protein. | ||
==About this Structure== | ==About this Structure== | ||
2BMI is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Bacteroides_fragilis Bacteroides fragilis] with ZN and NA as [http://en.wikipedia.org/wiki/ligands ligands]. This structure | 2BMI is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Bacteroides_fragilis Bacteroides fragilis] with <scene name='pdbligand=ZN:'>ZN</scene> and <scene name='pdbligand=NA:'>NA</scene> as [http://en.wikipedia.org/wiki/ligands ligands]. This structure supersedes the now removed PDB entry 1BMI. Active as [http://en.wikipedia.org/wiki/Beta-lactamase Beta-lactamase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=3.5.2.6 3.5.2.6] Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2BMI OCA]. | ||
==Reference== | ==Reference== | ||
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[[Category: zinc]] | [[Category: zinc]] | ||
''Page seeded by [http:// | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 16:39:26 2008'' | ||
Revision as of 17:39, 21 February 2008
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METALLO-BETA-LACTAMASE
OverviewOverview
beta-Lactamases are extracellular or periplasmic bacterial enzymes which confer resistance to beta-lactam antibiotics. On the basis of their catalytic mechanisms, they can be divided into two major groups: active-site serine enzymes (classes A, C and D) and the ZnII enzymes (class B). The first crystal structure of a class B enzyme, the metallo-beta-lactamase from Bacillus cereus, has been solved at 2.5 A resolution [Carfi, Pares, Duee, Galleni, Duez, Frere & Dideberg (1995). EMBO J. 14, 4914-4921]. Recently, the crystal structure of the metallo-beta-lactamase from Bacteroides fragilis has been determined in a tetragonal space group [Concha, Rasmussen, Bush & Herzberg (1996). Structure, 4, 823-836]. The structure of the metallo-beta-lactamase from B. fragilis in an orthorhombic crystal form at 2.0 A resolution is reported here. The final crystallographic R is 0.196 for all the 32501 observed reflections in the range 10-2.0 A. The refined model includes 458 residues, 437 water molecules, four zinc and two sodium ions. These structures are discussed with reference to Zn binding and activity. A catalytic mechanism is proposed which is coherent with metallo-beta-lactamases being active with either one Zn ion (as in Aeromonas hydrophila) or two Zn ions (as in B. fragilis) bound to the protein.
About this StructureAbout this Structure
2BMI is a Single protein structure of sequence from Bacteroides fragilis with and as ligands. This structure supersedes the now removed PDB entry 1BMI. Active as Beta-lactamase, with EC number 3.5.2.6 Full crystallographic information is available from OCA.
ReferenceReference
X-ray structure of the ZnII beta-lactamase from Bacteroides fragilis in an orthorhombic crystal form., Carfi A, Duee E, Paul-Soto R, Galleni M, Frere JM, Dideberg O, Acta Crystallogr D Biol Crystallogr. 1998 Jan 1;54(Pt 1):45-57. PMID:9761816
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