title: Crystal structure of AGR_C_4470p from Agrobacterium tumefaciens.
abstract: We report here the crystal structure at 2.0 A resolution of the AGR_C_4470p protein from the Gram-negative bacterium Agrobacterium tumefaciens. The protein is a tightly associated dimer, each subunit of which bears strong structural homology with the two domains of the heme utilization protein ChuS from Escherichia coli and HemS from Yersinia enterocolitica. Remarkably, the organization of the AGR_C_4470p dimer is the same as that of the two domains in ChuS and HemS, providing structural evidence that these two proteins evolved by gene duplication. However, the binding site for heme, while conserved in HemS and ChuS, is not conserved in AGR_C_4470p, suggesting that it probably has a different function. This is supported by the presence of two homologs of AGR_C_4470p in E. coli, in addition to the ChuS protein.
authors.affiliation: Department of Biological Sciences, Northeast Structural Genomics Consortium, Columbia University, New York, New York 10027, USA.
authors.forename: Sergey M
authors.initials: SM
authors.lastname: Vorobiev
authors.forename: Helen
authors.initials: H
authors.lastname: Neely
authors.forename: Jayaraman
authors.initials: J
authors.lastname: Seetharaman
authors.forename: Li-Chung
authors.initials: LC
authors.lastname: Ma
authors.forename: Rong
authors.initials: R
authors.lastname: Xiao
authors.forename: Thomas B
authors.initials: TB
authors.lastname: Acton
authors.forename: Gaetano T
authors.initials: GT
authors.lastname: Montelione
authors.forename: Liang
authors.initials: L
authors.lastname: Tong
mesh_terms: D016960:Agrobacterium tumefaciens / Q000378:metabolism*; D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000737:chemistry*; D001665:Binding Sites; D017124:Conserved Sequence; D018360:Crystallography, X-Ray; D019281:Dimerization; D006419:Heme Oxygenase (Decyclizing) / Q000737:chemistry; D026901:Membrane Transport Proteins / Q000737:chemistry*; D008958:Models, Molecular; D008969:Molecular Sequence Data; D010088:Oxidoreductases / Q000737:chemistry*; D011487:Protein Conformation; D016415:Sequence Alignment
chemical_list: D001426:Bacterial Proteins; C090995:HemS protein, Yersinia enterocolitica; D026901:Membrane Transport Proteins; D010088:Oxidoreductases; D006419:Heme Oxygenase (Decyclizing)