2dpe
From Proteopedia
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Crystal structure of a secretory 40KDA glycoprotein from sheep at 2.0A resolution
Overview
A 40kDa glycoprotein from dry secretion of sheep is implicated as a, signaling factor and is named as SPS-40. This protein is secreted only, during the early phase of involution when the drastic tissue remodeling, occurs in the mammary gland. SPS-40 was purified from sheep dry secretions, and crystallized using hanging drop vapour diffusion method. The crystals, belong to orthorhombic space group P2(1)2(1)2(1) with cell dimensions, a=62.7A, b=66.4A, c=107.5A. The protein was also cloned for the, determination of its complete amino acid sequence. The three-dimensional, structure of SPS-40 was determined by X-ray crystallographic method at, 2.0A resolution. The structure revealed the presence of an N-linked glycan, chain at Asn39. The protein adopts a conformation with a classical, (beta/alpha)(8)-barrel fold of triosephosphate isomerase (TIM) (residues, 1-237 and 310-360) with an insertion of a small (alpha+beta) domain, (residues 240-307) similar to that observed in chitinases. However, the, Leu substitution for Glu in the consensus catalytic sequence in SPS-40, causes a loss of chitinase activity. Furthermore, the sugar-binding groove, in SPS-40 is distorted considerably from the standard chitin-binding site, in chitinase enzymes and hence the binding of chitin-like oligosaccharides, is considerably hampered. Three surface loops, His188-His197, Phe202-Arg212 and Phe244-Pro260 have exceptionally high values of, B-factors (average=70.5A(2)), indicating the presence of a less defined, region.
About this Structure
2DPE is a Single protein structure of sequence from Ovis aries. This structure superseeds the now removed PDB entry 1R2V. Full crystallographic information is available from OCA.
Reference
Crystal structure of a secretory signalling glycoprotein from sheep at 2.0A resolution., Srivastava DB, Ethayathulla AS, Kumar J, Singh N, Sharma S, Das U, Srinivasan A, Singh TP, J Struct Biol. 2006 Dec;156(3):505-16. Epub 2006 Jun 8. PMID:16859926
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