1sgz

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Revision as of 17:07, 12 November 2007

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spinqualitylabelsall models 1sgz, resolution 2.0Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image

Crystal Structure of Unbound Beta-Secretase Catalytic Domain.

Overview

The three-dimensional structure of unbound human memapsin 2, (beta-secretase) protease domain determined at 2.0-A resolution has, revealed a new position of the flap region, which appears to be locked in, an "open" position. While the structure outside of the flap is essentially, the same as the structure of memapsin 2 bound to an inhibitor, the flap, positions are 4.5 A different at the tips. The open position of the flap, in the current structure is stabilized by two newly formed intraflap, hydrogen bonds and anchored by a new hydrogen bond involving the side, chain of Tyr 71 (Tyr 75 in pepsin numbering) in a novel orientation. In, molecular modeling experiments, the opening of the flap, 6.5 A at the, narrowest point, permits entrance of substrates into the cleft. The, narrowest point of the opening may function to discriminate among, substrates based on sequence and shape. The observed flap opening may also, serve as a model for the flap movement in the catalytic mechanism of, eukaryotic aspartic proteases and provide insight for the side-chain, selection in the design of memapsin 2 inhibitors.

About this Structure

1SGZ is a Single protein structure of sequence from Homo sapiens. Active as Memapsin 2, with EC number 3.4.23.46 Full crystallographic information is available from OCA.

Reference

Flap position of free memapsin 2 (beta-secretase), a model for flap opening in aspartic protease catalysis., Hong L, Tang J, Biochemistry. 2004 Apr 27;43(16):4689-95. PMID:15096037

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