4caa

CLEAVED ANTICHYMOTRYPSIN T345R

spinqualitylabelsall models 4caa, resolution 2.90Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 4caa is a 2 chain structure with sequence from Homo sapiens. This structure supersedes the now removed PDB entry 1ct3. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Gene: ACT (Homo sapiens) Resources: FirstGlance, OCA, RCSB, PDBsum 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 PubMed Expressed in a kinetically trapped folding state, a serpin couples the thermodynamic driving force of a massive beta-sheet rearrangement to the inhibition of a target protease. Hence, the serpin-protease interaction is the premier example of a "spring-loaded" protein-protein interaction. Amino acid substitutions in the hinge region of a serpin reactive loop can weaken the molecular spring, which converts the serpin from an inhibitor into a substrate. To probe the molecular basis of this conversion, we report the crystal structure of A349R antichymotrypsin in the reactive loop cleaved state at 2.1 A resolution. This amino acid substitution does not block the beta-sheet rearrangement despite the burial of R349 in the hydrophobic core of the cleaved serpin along with a salt-linked acetate ion. The inhibitory activity of this serpin variant is not obliterated; remarkably, its inhibitory properties are anion-dependent due to the creation of an anion-binding cavity in the cleaved serpin. Engineering an anion-binding cavity in antichymotrypsin modulates the "spring-loaded" serpin-protease interaction.,Lukacs CM, Rubin H, Christianson DW Biochemistry. 1998 Mar 10;37(10):3297-304. PMID:9521649 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

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