1poh
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(New page: 200px<br /><applet load="1poh" size="450" color="white" frame="true" align="right" spinBox="true" caption="1poh, resolution 2.0Å" /> '''THE 2.0 ANGSTROMS RES...)
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Revision as of 21:51, 20 November 2007
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THE 2.0 ANGSTROMS RESOLUTION STRUCTURE OF ESCHERICHIA COLI HISTIDINE-CONTAINING PHOSPHOCARRIER PROTEIN HPR: A REDETERMINATION
Overview
The x-ray structure of Escherichia coli HPr has been redetermined at 2.0-A, resolution. In contrast to the previous study (El-Kabbani, O. A. L., Waygood, E. B., and Delbaere, L. T. J. (1987) J. Biol. Chem. 262, 12926-12929), the overall structure is, in general, similar to other, reported NMR and x-ray HPr structures, although there are some important, differences in detail. The overall folding topology of HPr is a classical, open-faced beta-sandwich, consisting of four antiparallel beta-strands and, three alpha-helices. The least square refinement produced an R index of, 0.135 for all measured unique data between 8.0 and 2.0 A resolution. The, active center consists of His15 which is hydrogen bonded to a sulfate, anion, and Arg17 which has a fully open conformation. This corresponds to, the first observed "semi-closed" conformation of the active center of HPr., The Streptococcus faecalis HPr structure (Jia, Z., Vandonselaar, M., Quail, J. W., and Delbaere, L. T. J. (1993) Nature 361, 94-97) has the, "open" conformation in which the side chains of His15 and Arg17 are, directed as far away from each other as possible. The Bacillus subtilis, HPr (Herzberg, O., Reddy, P., Sutrina, S., Saier, M. H., Jr., Reizer, J., and Kapadia, G. (1992) Proc. Natl. Acad. Sci. U.S.A. 89, 2499-2503) has, the "closed" conformation in which the side chains of His15 and Arg17 are, close together with a sulfate anion located in the active center. The open, conformation represents the unphosphorylated form of HPr whereas the, closed conformation likely resembles the phosphorylated form of HPr. The, semi-closed conformation observed in the E. coli HPr structure could, represent a structural intermediate on the, phosphorylation/dephosphorylation pathway of HPr.
About this Structure
1POH is a Single protein structure of sequence from Escherichia coli with SO4 as ligand. Full crystallographic information is available from OCA.
Reference
The 2.0-A resolution structure of Escherichia coli histidine-containing phosphocarrier protein HPr. A redetermination., Jia Z, Quail JW, Waygood EB, Delbaere LT, J Biol Chem. 1993 Oct 25;268(30):22490-501. PMID:8226757
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