1poh
From Proteopedia
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. 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 Page seeded by OCA on Sat May 3 05:18:32 2008
