2cck
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CRYSTAL STRUCTURE OF UNLIGANDED S. AUREUS THYMIDYLATE KINASE
OverviewOverview
Methicillin-resistant Staphylococcus aureus (MRSA) poses a major threat to, human health, particularly through hospital acquired infection. The spread, of MRSA means that novel targets are required to develop potential, inhibitors to combat infections caused by such drug-resistant bacteria., Thymidylate kinase (TMK) is attractive as an antibacterial target as it is, essential for providing components for DNA synthesis. Here, we report, crystal structures of unliganded and thymidylate-bound forms of S. aureus, thymidylate kinase (SaTMK). His-tagged and untagged SaTMK crystallize with, differing lattice packing and show variations in conformational states for, unliganded and thymidylate (TMP) bound forms. In addition to open and, closed forms of SaTMK, an intermediate conformation in TMP binding is, observed, in which the site is partially closed. Analysis of these, structures indicates a sequence of events upon TMP binding, with helix, alpha3 shifting position initially, followed by movement of alpha2 to, close the substrate site. In addition, we observe significant, conformational differences in the TMP-binding site in SaTMK as compared to, available TMK structures from other bacterial species, Escherichia coli, and Mycobacterium tuberculosis as well as human TMK. In SaTMK, Arg 48 is, situated at the base of the TMP-binding site, close to the thymine ring, whereas a cis-proline occupies the equivalent position in other TMKs. The, observed TMK structural differences mean that design of compounds highly, specific for the S. aureus enzyme looks possible; such inhibitors could, minimize the transfer of drug resistance between different bacterial, species.
About this StructureAbout this Structure
2CCK is a Single protein structure of sequence from Staphylococcus aureus with CL and EDO as ligands. Active as dTMP kinase, with EC number 2.7.4.9 Structure known Active Site: AC1. Full crystallographic information is available from OCA.
ReferenceReference
Structures of S. aureus thymidylate kinase reveal an atypical active site configuration and an intermediate conformational state upon substrate binding., Kotaka M, Dhaliwal B, Ren J, Nichols CE, Angell R, Lockyer M, Hawkins AR, Stammers DK, Protein Sci. 2006 Apr;15(4):774-84. Epub 2006 Mar 7. PMID:16522804
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