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Crystal Structure of Escherichia coli Protein ybgI



Jane E. Ladner, G Obmolova, A Teplyakov, P P. Khil, R D. Camerini-Otero, G L. Gilliland


The crystal structure determination of E. coli protein ybgI was undertaken as part of a structural genomics effort ( in order to assist with the functional assignment of the protein. The protein encoded by the ybgI gene of Escherichia coli is 247 residues in length and has a molecular weight of 27 kDa. It belongs to the DUF34 family of proteins. No biological function is known for members of this sequentially related family of, at present, 67 proteins. The protein ybgI is a sequence homolog of Haemophilus influenzae HI0105 with a sequence identity of 59 %. The ybgI protein was cloned, expressed and the crystal structure was determined to 2.2 resolution. The ybgI protein consists of two similar interlinked [alpha]/ domains; both are 3-layer sandwiches (alpha-beta-alpha). The crystallographic asymmetric unit contains three dimers. The application of the three-fold crystal symmetry reveals that the quaternary structure is a toroid formed by three crystallographically related dimers. In the crystals, these toroids stack forming long tubes. The toroidal ring quaternary structure brings to mind many proteins that are involved in DNA metabolism. The most likely region for the active site is a group of conserved residues which include four histidines (63, 64, 97, 215), two glutamic acids (194, 219), one aspartic acid (101), one asparagine (108), one cysteine (171), one tyrosine (22) and one tryptophan (68). There are also two metal ions 3.3 apart bound by this cluster of residues in the selenomethione protein. Biochemical studies to further profile the function of the ybgI protein are in progress.
Proteins-Structure Function And Genetics


crystal structure, DNA metabolism, Escherichia coli, metalloprotein, structural genomics


Ladner, J. , Obmolova, G. , Teplyakov, A. , Khil, P. , Camerini-Otero, R. and Gilliland, G. (2021), Crystal Structure of Escherichia coli Protein ybgI, Proteins-Structure Function And Genetics (Accessed April 21, 2024)
Created October 12, 2021