1bv4
From Proteopedia
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APO-MANNOSE-BINDING PROTEIN-C
Overview
C-type animal lectins are a diverse family of proteins which mediate cell-surface carbohydrate-recognition events through a conserved carbohydrate-recognition domain (CRD). Most members of this family possess a carbohydrate-binding activity that depends strictly on the binding of Ca2+ at two sites, designated 1 and 2, in the CRD. The structural transitions associated with Ca2+ binding in C-type lectins have been investigated by determining high-resolution crystal structures of rat serum mannose-binding protein (MBP) bound to one Ho3+ in place of Ca2+, and the apo form of rat liver MBP. The removal of Ca2+ does not affect the core structure of the CRD, but dramatic conformational changes occur in the loops. The most significant structural change in the absence of Ca2+ is the isomerization of a cis-peptide bond preceding a conserved proline residue in Ca2+ site 2. This bond adopts the cis conformation in all Ca2+-bound structures, whereas both cis and trans conformations are observed in the absence of Ca2+. The pattern of structural changes in the three loops that interact with Ca2+ is dictated in large part by the conformation of the prolyl peptide bond. The highly conserved nature of Ca2+ site 2 suggests that the transitions observed in MBPs are general features of Ca2+ binding in C-type lectins.
About this Structure
1BV4 is a Single protein structure of sequence from Rattus norvegicus. Full crystallographic information is available from OCA.
Reference
Ca2+-dependent structural changes in C-type mannose-binding proteins., Ng KK, Park-Snyder S, Weis WI, Biochemistry. 1998 Dec 22;37(51):17965-76. PMID:9922165
Page seeded by OCA on Thu Feb 21 11:59:29 2008
