1w79: Difference between revisions

Actinomadura sp. R39 produces an exocellular, DD-peptidase/penicillin-binding protein (PBP) whose primary structure is, similar to that of Escherichia coli PBP4. It is characterized by a high, beta-lactam-binding activity (second order rate constant for the acylation, of the active site serine by benzylpenicillin: k2/K = 300 mm(-1) s(-1))., The crystal structure of the DD-peptidase from Actinomadura R39 was solved, at a resolution of 1.8 angstroms by single anomalous dispersion at the, cobalt resonance wavelength. The structure is composed of three domains: a, penicillin-binding domain similar to the penicillin-binding domain of E., coli PBP5 and two domains of unknown function. In most multimodular PBPs, additional domains are generally located at the C or N termini of the, penicillin-binding domain. In R39, the other two domains are inserted in, the penicillin-binding domain, between the SXXK and SXN motifs, in a, manner similar to "Matryoshka dolls." One of these domains is composed of, a five-stranded beta-sheet with two helices on one side, and the other, domain is a double three-stranded beta-sheet inserted in the previous, domain. Additionally, the 2.4-angstroms structure of the acyl-enzyme, complex of R39 with nitrocefin reveals the absence of active site, conformational change upon binding the beta-lactams.

1W79 is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/ ] with SO4 and MG as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [http://en.wikipedia.org/wiki/Serine-type_D-Ala-D-Ala_carboxypeptidase Serine-type D-Ala-D-Ala carboxypeptidase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=3.4.16.4 3.4.16.4] Structure known Active Site: AC1. Full crystallographic information is available from [http://ispc.weizmann.ac.il/oca-bin/ocashort?id=1W79 OCA].  

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