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Publication Abstract from PubMed

The psychrophilic organism Colwellia psychrerythraea strain 34H produces extracellular polysaccharide substances to tolerate cold environments. Sedoheptulose 7-phosphate isomerase (GmhA) is essential for producing Dglycero-D-mannoheptose 7-phosphate, a key mediator in the lipopolysaccharide biosynthetic pathway. We determined the crystal structure of GmhA from C. psychrerythraea strain 34H (CpsGmhA, UniProtKB code: Q47VU0) at a resolution of 2.8 A. The tetrameric structure is similar to that of homologous GmhA structures. Interestingly, one of the catalytic residues, glutamate, which has been reported to be critical for the activity of other homologous GmhA enzymes, is replaced by a glutamine residue in the CpsGmhA protein. We also found differences in the conformations of several other catalytic residues. Extensive structural and sequence analyses reveal that CpsGmhA shows high similarity to Escherichia coli DnaA initiatorassociating protein A (DiaA). Therefore, the CpsGmhA structure reported here may provide insight into the structural and functional correlations between GmhA and DiaA among specific microorganisms.

Crystal Structure and Comparative Sequence Analysis of GmhA from Colwellia psychrerythraea Strain 34H Provides Insight into Functional Similarity with DiaA.,Do H, Yun JS, Lee CW, Choi YJ, Kim HY, Kim YJ, Park H, Chang JH, Lee JH Mol Cells. 2015 Nov 26. doi: 10.14348/molcells.2015.0191. PMID:26612680^[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.