3V3R

Crystal Structure of GES-11

Summary for 3V3R

• Entry DOI: 10.2210/pdb3v3r/pdb
• Related: 2QPN
• Descriptor: Extended spectrum class A beta-lactamase GES-11, IODIDE ION, SODIUM ION, ... (4 entities in total)
• Functional Keywords: beta lactamase fold, hydrolase, beta lactams
• Biological source: Acinetobacter baumannii
• Total number of polymer chains: 2
• Total formula weight: 65354.71

Authors

Delbruck, H.,Hoffmann, K.M.V.,Bebrone, C. (deposition date: 2011-12-14, release date: 2012-09-26, Last modification date: 2024-10-09)

Primary citation

Delbruck, H.,Bogaerts, P.,Kupper, M.B.,Rezende de Castro, R.,Bennink, S.,Glupczynski, Y.,Galleni, M.,Hoffmann, K.M.,Bebrone, C.
Kinetic and crystallographic studies of extended-spectrum GES-11, GES-12, and GES-14 beta-lactamases.
Antimicrob.Agents Chemother., 56:5618-5625, 2012

PubMed Abstract: GES-1 is a class A extended-spectrum β-lactamase conferring resistance to penicillins, narrow- and expanded-spectrum cephalosporins, and ceftazidime. However, GES-1 poorly hydrolyzes aztreonam and cephamycins and exhibits very low k(cat) values for carbapenems. Twenty-two GES variants have been discovered thus far, differing from each other by 1 to 3 amino acid substitutions that affect substrate specificity. GES-11 possesses a Gly243Ala substitution which seems to confer to this variant an increased activity against aztreonam and ceftazidime. GES-12 differs from GES-11 by a single Thr237Ala substitution, while GES-14 differs from GES-11 by the Gly170Ser mutation, which is known to confer increased carbapenemase activity. GES-11 and GES-12 were kinetically characterized and compared to GES-1 and GES-14. Purified GES-11 and GES-12 showed strong activities against most tested β-lactams, with the exception of temocillin, cefoxitin, and carbapenems. Both variants showed a significantly increased rate of hydrolysis of cefotaxime, ceftazidime, and aztreonam. On the other hand, GES-11 and GES-12 (and GES-14) variants all containing Ala243 exhibited increased susceptibility to classical inhibitors. The crystallographic structures of the GES-11 and GES-14 β-lactamases were solved. The overall structures of GES-11 and GES-14 are similar to that of GES-1. The Gly243Ala substitution caused only subtle local rearrangements, notably in the typical carbapenemase disulfide bond. The active sites of GES-14 and GES-11 are very similar, with the Gly170Ser substitution leading only to the formation of additional hydrogen bonds of the Ser residue with hydrolytic water and the Glu166 residue.

PubMed: 22908160
DOI: 10.1128/AAC.01272-12

Experimental method

X-RAY DIFFRACTION (1.898 Å)