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2pul
From Proteopedia
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| , resolution 2.00Å | |||||||
|---|---|---|---|---|---|---|---|
| Ligands: | , and | ||||||
| Gene: | mtnK, ykrT (Bacillus subtilis) | ||||||
| Activity: | S-methyl-5-thioribose kinase, with EC number 2.7.1.100 | ||||||
| Coordinates: | save as pdb, mmCIF, xml | ||||||
Structures of 5-methylthioribose kinase reveal substrate specificity and unusual mode of nucleotide binding
Overview
The methionine salvage pathway is ubiquitous in all organisms, but metabolic variations exist between bacteria and mammals. 5-Methylthioribose (MTR) kinase is a key enzyme in methionine salvage in bacteria and the absence of a mammalian homolog suggests that it is a good target for the design of novel antibiotics. The structures of the apo-form of Bacillus subtilis MTR kinase, as well as its ADP, ADP-PO(4), AMPPCP, and AMPPCP-MTR complexes have been determined. MTR kinase has a bilobal eukaryotic protein kinase fold but exhibits a number of unique features. The protein lacks the DFG motif typically found at the beginning of the activation loop and instead coordinates magnesium via a DXE motif (Asp(250)-Glu(252)). In addition, the glycine-rich loop of the protein, analogous to the "Gly triad" in protein kinases, does not interact extensively with the nucleotide. The MTR substrate-binding site consists of Asp(233) of the catalytic HGD motif, a novel twin arginine motif (Arg(340)/Arg(341)), and a semi-conserved W-loop, which appears to regulate MTR binding specificity. No lobe closure is observed for MTR kinase upon substrate binding. This is probably because the enzyme lacks the lobe closure/inducing interactions between the C-lobe of the protein and the ribosyl moiety of the nucleotide that are typically responsible for lobe closure in protein kinases. The current structures suggest that MTR kinase has a dissociative mechanism.
About this Structure
2PUL is a Single protein structure of sequence from Bacillus subtilis. Full crystallographic information is available from OCA.
Reference
Structures of 5-methylthioribose kinase reveal substrate specificity and unusual mode of nucleotide binding., Ku SY, Yip P, Cornell KA, Riscoe MK, Behr JB, Guillerm G, Howell PL, J Biol Chem. 2007 Jul 27;282(30):22195-206. Epub 2007 May 23. PMID:17522047
Page seeded by OCA on Thu Mar 20 18:17:38 2008
