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NMR Structure of Citrobacter freundii AmpD, Comparison with Bacteriophage T7 Lysozyme and Homology with PGRP Domains
- Source :
-
Journal of Molecular Biology . Apr2003, Vol. 327 Issue 4, p833. 10p. - Publication Year :
- 2003
-
Abstract
- AmpD is a bacterial amidase involved in the recycling of cell-wall fragments in Gram-negative bacteria. Inactivation of AmpD leads to derepression of β-lactamase expression, presenting a major pathway for the acquisition of constitutive antibiotic resistance. Here, we report the NMR structure of AmpD from Citrobacter freundii (PDB accession code 1J3G). A deep substrate-binding pocket explains the observed specificity for low molecular mass substrates. The fold is related to that of bacteriophage T7 lysozyme. Both proteins bind zinc at a conserved site and require zinc for amidase activity, although the enzymatic mechanism seems to differ in detail. The structure-based sequence alignment identifies conserved features that are also conserved in the eukaryotic peptidoglycan recognition protein (PGRP) domains, including the zinc-coordination site in several of them. PGRP domains thus belong to the same fold family and, where zinc-binding residues are conserved, may have amidase activity. This hypothesis is supported by the observation that human serum N-acetylmuramyl-l-alanine amidase seems to be identical with a soluble form of human PGRP-L. [Copyright &y& Elsevier]
Details
- Language :
- English
- ISSN :
- 00222836
- Volume :
- 327
- Issue :
- 4
- Database :
- Academic Search Index
- Journal :
- Journal of Molecular Biology
- Publication Type :
- Academic Journal
- Accession number :
- 9344226
- Full Text :
- https://doi.org/10.1016/S0022-2836(03)00185-2