1zym

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spinqualitylabelsall models 1zym, resolution 2.5Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image

AMINO TERMINAL DOMAIN OF ENZYME I FROM ESCHERICHIA COLI

Overview

BACKGROUND: The bacterial phosphoenolpyruvate (PEP): sugar, phosphotransferase system (PTS) transports exogenous hexose sugars through, the membrane and tightly couples transport with phosphoryl transfer from, PEP to the sugar via several phosphoprotein intermediates. The phosphate, group is first transferred to enzyme I, second to the histidine-containing, phosphocarrier protein HPr, and then to one of a number of sugar-specific, enzymes II. The structures of several HPrs and enzymes IIA are known. Here, we report the structure of the N-terminal half of enzyme I from, Escherichia coli (EIN). RESULTS: The crystal structure of EIN (MW, approximately 30 kDa) has been determined and refined at 2.5 A resolution., It has two distinct structural subdomains; one contains four alpha helices, arranged as two hairpins in a claw-like conformation. The other consists, of a beta sandwich containing a three-stranded antiparallel beta sheet and, a four-stranded parallel beta sheet, together with three short alpha, helices. Plausible models of complexes between EIN and HPr can be made, without assuming major structural changes in either protein. CONCLUSIONS:, The alpha/beta subdomain of EIN is topologically similar to the, phosphohistidine domain of the enzyme pyruvate phosphate dikinase, which, is phosphorylated by PEP on a histidyl residue but does not interact with, HPr. It is therefore likely that features of this subdomain are important, in the autophosphorylation of enzyme I. The helical subdomain of EIN is, not found in pyruvate phosphate dikinase; this subdomain is therefore more, likely to be involved in phosphoryl transfer to HPr.

About this Structure

1ZYM is a Single protein structure of sequence from Escherichia coli. Active as Phosphoenolpyruvate--protein phosphotransferase, with EC number 2.7.3.9 Full crystallographic information is available from OCA.

Reference

The first step in sugar transport: crystal structure of the amino terminal domain of enzyme I of the E. coli PEP: sugar phosphotransferase system and a model of the phosphotransfer complex with HPr., Liao DI, Silverton E, Seok YJ, Lee BR, Peterkofsky A, Davies DR, Structure. 1996 Jul 15;4(7):861-72. PMID:8805571

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