Structural highlights
4mut is a 2 chain structure with sequence from Atcc 49573. Full crystallographic information is available from OCA.
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| Ligands: | CL, DAL, PE3, SO4, ZN
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| Related: | 4muq, 4mur, 4mus, 4f78, 4oak |
| Gene: | vanXYc (ATCC 49573) |
| Activity: | Glucokinase, with EC number 2.7.1.2 |
| Resources: | FirstGlance, OCA, RCSB, PDBsum |
Publication Abstract from PubMed
Vancomycin resistance in Gram-positive bacteria is due to production of cell-wall precursors ending in d-Ala-d-Lac or d-Ala-d-Ser, to which vancomycin exhibits low binding affinities, and to the elimination of the high-affinity precursors ending in d-Ala-d-Ala. Depletion of the susceptible high-affinity precursors is catalyzed by the zinc-dependent d,d-peptidases VanX and VanY acting on dipeptide (d-Ala-d-Ala) or pentapeptide (UDP-MurNac-l-Ala-d-Glu-l-Lys-d-Ala-d-Ala), respectively. Some of the vancomycin resistance operons encode VanXY d,d-carboxypeptidase, which hydrolyzes both di- and pentapeptide. The molecular basis for the diverse specificity of Van d,d-peptidases remains unknown. We present the crystal structures of VanXYC and VanXYG in apo and transition state analog-bound forms and of VanXYC in complex with the d-Ala-d-Ala substrate and d-Ala product. Structural and biochemical analysis identified the molecular determinants of VanXY dual specificity. VanXY residues 110-115 form a mobile cap over the catalytic site, whose flexibility is involved in the switch between di- and pentapeptide hydrolysis. Structure-based alignment of the Van d,d-peptidases showed that VanY enzymes lack this element, which promotes binding of the penta- rather than that of the dipeptide. The structures also highlight the molecular basis for selection of d-Ala-ending precursors over the modified resistance targets. These results illustrate the remarkable adaptability of the d,d-peptidase fold in response to antibiotic pressure via evolution of specific structural elements that confer hydrolytic activity against vancomycin-susceptible peptidoglycan precursors.
Structural basis for the evolution of vancomycin resistance D,D-peptidases.,Meziane-Cherif D, Stogios PJ, Evdokimova E, Savchenko A, Courvalin P Proc Natl Acad Sci U S A. 2014 Apr 7. PMID:24711382[1]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
References
