2blm: Difference between revisions
New page: left|200px<br /><applet load="2blm" size="450" color="white" frame="true" align="right" spinBox="true" caption="2blm, resolution 2.0Å" /> '''BETA-LACTAMASE OF BAC... |
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[[Image:2blm.jpg|left|200px]]<br /><applet load="2blm" size=" | [[Image:2blm.jpg|left|200px]]<br /><applet load="2blm" size="350" color="white" frame="true" align="right" spinBox="true" | ||
caption="2blm, resolution 2.0Å" /> | caption="2blm, resolution 2.0Å" /> | ||
'''BETA-LACTAMASE OF BACILLUS LICHENIFORMIS 749(SLASH)C AT 2 ANGSTROMS RESOLUTION'''<br /> | '''BETA-LACTAMASE OF BACILLUS LICHENIFORMIS 749(SLASH)C AT 2 ANGSTROMS RESOLUTION'''<br /> | ||
==Overview== | ==Overview== | ||
Two crystal forms (A and B) of the 29,500 Da Class A beta-lactamase | Two crystal forms (A and B) of the 29,500 Da Class A beta-lactamase (penicillinase) from Bacillus licheniformis 749/C have been examined crystallographically. The structure of B-form crystals has been solved to 2 A resolution, the starting model for which was a 3.5 A structure obtained from A-form crystals. The beta-lactamase has an alpha + beta structure with 11 helices and 5 beta-strands seen also in a penicillin target DD-peptidase of Streptomyces R61. Atomic parameters of the two molecules in the asymmetric unit were refined by simulated annealing at 2.0 A resolution. The R factor is 0.208 for the 27,330 data greater than 3 sigma (F), with water molecules excluded from the model. The catalytic Ser-70 is at the N-terminus of a helix and is within hydrogen bonding distance of conserved Lys-73. Also interacting with the Lys-73 are Asn-132 and the conserved Glu-166, which is on a potentially flexible helix-containing loop. The structure suggests the binding of beta-lactam substrates is facilitated by interactions with Lys-234, Thr-235, and Ala-237 in a conserved beta-strand peptide, which is antiparallel to the beta-lactam's acylamido linkage; an exposed cavity near Asn-170 exists for acylamido substituents. The reactive double bond of clavulanate-type inhibitors may interact with Arg-244 on the fourth beta-strand. A very similar binding site architecture is seen in the DD-peptidase. | ||
==About this Structure== | ==About this Structure== | ||
2BLM is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Bacillus_licheniformis Bacillus licheniformis]. 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:// | 2BLM is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Bacillus_licheniformis Bacillus licheniformis]. 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=2BLM OCA]. | ||
==Reference== | ==Reference== | ||
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[[Category: Single protein]] | [[Category: Single protein]] | ||
[[Category: Dideberg, O.]] | [[Category: Dideberg, O.]] | ||
[[Category: Knox, J | [[Category: Knox, J R.]] | ||
[[Category: Moews, P | [[Category: Moews, P C.]] | ||
[[Category: hydrolase(acting in cyclic amides)]] | [[Category: hydrolase(acting in cyclic amides)]] | ||
''Page seeded by [http:// | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 16:39:07 2008'' | ||
Revision as of 17:39, 21 February 2008
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BETA-LACTAMASE OF BACILLUS LICHENIFORMIS 749(SLASH)C AT 2 ANGSTROMS RESOLUTION
OverviewOverview
Two crystal forms (A and B) of the 29,500 Da Class A beta-lactamase (penicillinase) from Bacillus licheniformis 749/C have been examined crystallographically. The structure of B-form crystals has been solved to 2 A resolution, the starting model for which was a 3.5 A structure obtained from A-form crystals. The beta-lactamase has an alpha + beta structure with 11 helices and 5 beta-strands seen also in a penicillin target DD-peptidase of Streptomyces R61. Atomic parameters of the two molecules in the asymmetric unit were refined by simulated annealing at 2.0 A resolution. The R factor is 0.208 for the 27,330 data greater than 3 sigma (F), with water molecules excluded from the model. The catalytic Ser-70 is at the N-terminus of a helix and is within hydrogen bonding distance of conserved Lys-73. Also interacting with the Lys-73 are Asn-132 and the conserved Glu-166, which is on a potentially flexible helix-containing loop. The structure suggests the binding of beta-lactam substrates is facilitated by interactions with Lys-234, Thr-235, and Ala-237 in a conserved beta-strand peptide, which is antiparallel to the beta-lactam's acylamido linkage; an exposed cavity near Asn-170 exists for acylamido substituents. The reactive double bond of clavulanate-type inhibitors may interact with Arg-244 on the fourth beta-strand. A very similar binding site architecture is seen in the DD-peptidase.
About this StructureAbout this Structure
2BLM is a Single protein structure of sequence from Bacillus licheniformis. Active as Beta-lactamase, with EC number 3.5.2.6 Full crystallographic information is available from OCA.
ReferenceReference
Beta-lactamase of Bacillus licheniformis 749/C at 2 A resolution., Moews PC, Knox JR, Dideberg O, Charlier P, Frere JM, Proteins. 1990;7(2):156-71. PMID:2326252
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