title: Crystal Structure and Comparative Sequence Analysis of GmhA from Colwellia psychrerythraea Strain 34H Provides Insight into Functional Similarity with DiaA.
abstract: The psychrophilic organism Colwellia psychrerythraea strain 34H produces extracellular polysaccharide substances to tolerate cold environments. Sedoheptulose 7-phosphate isomerase (GmhA) is essential for producing d-glycero-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 Å. 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 initiator-associating 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.
authors.affiliation: Division of Polar Life Sciences, Korea Polar Research Institute, Incheon 406-840, Korea.
authors.forename: Hackwon
authors.initials: H
authors.lastname: Do
authors.affiliation: Department of Biology Education, Kyungpook National University, Daegu 702-701, Korea.
authors.forename: Ji-Sook
authors.initials: JS
authors.lastname: Yun
authors.affiliation: Division of Polar Life Sciences, Korea Polar Research Institute, Incheon 406-840, Korea.|Department of Polar Sciences, University of Science and Technology, Incheon 406-840, Korea.
authors.forename: Chang Woo
authors.initials: CW
authors.lastname: Lee
authors.affiliation: Department of Biology Education, Kyungpook National University, Daegu 702-701, Korea.
authors.forename: Young Jun
authors.initials: YJ
authors.lastname: Choi
authors.affiliation: Protein Structure Group, Korea Basic Science Institute, Chungbuk 363-883, Korea.
authors.forename: Hye-Yeon
authors.initials: HY
authors.lastname: Kim
authors.affiliation: Department of Marine Science, Incheon National University, Incheon 406-772, Korea.
authors.forename: Youn-Jung
authors.initials: YJ
authors.lastname: Kim
authors.affiliation: Division of Polar Life Sciences, Korea Polar Research Institute, Incheon 406-840, Korea.|Department of Polar Sciences, University of Science and Technology, Incheon 406-840, Korea.
authors.forename: Hyun
authors.initials: H
authors.lastname: Park
authors.affiliation: Department of Biology Education, Kyungpook National University, Daegu 702-701, Korea.
authors.forename: Jeong Ho
authors.initials: JH
authors.lastname: Chang
authors.affiliation: Division of Polar Life Sciences, Korea Polar Research Institute, Incheon 406-840, Korea.|Department of Polar Sciences, University of Science and Technology, Incheon 406-840, Korea.
authors.forename: Jun Hyuck
authors.initials: JH
authors.lastname: Lee
mesh_terms: D001426:Bacterial Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D002352:Carrier Proteins / Q000737:chemistry*; D020134:Catalytic Domain; D003001:Cloning, Molecular; D018360:Crystallography, X-Ray; D020563:Gammaproteobacteria / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D005973:Glutamine / Q000378:metabolism; D008958:Models, Molecular; D011487:Protein Conformation; D019998:Racemases and Epimerases / Q000737:chemistry* / Q000235:genetics* / Q000378:metabolism; D020539:Sequence Analysis, Protein / Q000379:methods*; D040681:Structural Homology, Protein
chemical_list: D001426:Bacterial Proteins; D002352:Carrier Proteins; C523634:DiaA protein, E coli; D005973:Glutamine; D019998:Racemases and Epimerases
keywords: Colwellia psychrerythraea strain 34H; CpsGmhA; DiaA; psychrophile; sedoheptulose 7-phosphate isomerase