1h7f
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| , resolution 2.12Å | |||||||
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| Sites: | |||||||
| Ligands: | |||||||
| Gene: | KPSU (Escherichia coli) | ||||||
| Activity: | 3-deoxy-manno-octulosonate cytidylyltransferase, with EC number 2.7.7.38 | ||||||
| Resources: | FirstGlance, OCA, PDBsum, RCSB | ||||||
| Coordinates: | save as pdb, mmCIF, xml | ||||||
THE STRUCTURE OF CMP:2-KETO-3-DEOXY-MANNO-OCTONIC ACID SYNTHETASE AND OF ITS COMPLEXES WITH SUBSTRATES AND SUBSTRATE ANALOGUES, CMP COMPLEX
OverviewOverview
The enzyme CMP-Kdo synthetase (CKS) catalyzes the activation of the sugar Kdo (2-keto-3-deoxy-manno-octonic acid) by forming a monophosphate diester. CKS is a pharmaceutical target because CMP-Kdo is used in the biosynthesis of lipopolysaccharides that are vital for Gram-negative bacteria. We have refined the structure of the unligated capsule-specific CKS from Escherichia coli at 1.8 A resolution (1 A=0.1 nm) and we have established the structures of its complexes with the substrate CTP, with CDP and CMP as well as with the product analog CMP-NeuAc (CMP-sialate) by X-ray diffraction analyses at resolutions between 2.1 A and 2.5 A. The N-terminal domains of the dimeric enzyme bind CTP in a peculiar nucleotide-binding fold, whereas the C-terminal domains form the dimer interface. The observed binding geometries together with the amino acid variabilities during evolution and the locations of a putative Mg(2+) and of a very strongly bound water molecule suggest a pathway for the catalysis. The N-terminal domain shows sequence homology with the CMP-NeuAc synthetases. Moreover, the chain fold and the substrate-binding position of CKS resemble those of other enzymes processing nucleotide-sugars.
About this StructureAbout this Structure
1H7F is a Single protein structure of sequence from Escherichia coli. Full crystallographic information is available from OCA.
ReferenceReference
The structure of CMP:2-keto-3-deoxy-manno-octonic acid synthetase and of its complexes with substrates and substrate analogs., Jelakovic S, Schulz GE, J Mol Biol. 2001 Sep 7;312(1):143-55. PMID:11545592
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