1sgz
Crystal Structure of Unbound Beta-Secretase Catalytic Domain.
Structural highlights
FunctionBACE1_HUMAN Responsible for the proteolytic processing of the amyloid precursor protein (APP). Cleaves at the N-terminus of the A-beta peptide sequence, between residues 671 and 672 of APP, leads to the generation and extracellular release of beta-cleaved soluble APP, and a corresponding cell-associated C-terminal fragment which is later released by gamma-secretase.[1] [2] Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedThe 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. 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[3] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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