1I0A

CRYSTAL STRUCTURE OF WILD TYPE TURKEY DELTA 1 CRYSTALLIN (EYE LENS PROTEIN)

1I0A の概要

• エントリーDOI: 10.2210/pdb1i0a/pdb
• 関連するPDBエントリー: 1DCN 1HY0 1HY1
• 分子名称: DELTA CRYSTALLIN I (2 entities in total)
• 機能のキーワード: eye lens protein, delta 1 crystallin, argininosuccinate lyase, lyase
• 由来する生物種: Meleagris gallopavo (turkey)
• タンパク質・核酸の鎖数: 4
• 化学式量合計: 203570.83

構造登録者

Sampaleanu, L.M.,Vallee, F.,Slingsby, C.,Howell, P.L. (登録日: 2001-01-29, 公開日: 2001-04-21, 最終更新日: 2024-02-07)

主引用文献

Sampaleanu, L.M.,Vallee, F.,Slingsby, C.,Howell, P.L.
Structural studies of duck delta 1 and delta 2 crystallin suggest conformational changes occur during catalysis.
Biochemistry, 40:2732-2742, 2001

PubMed Abstract: Duck delta1 and delta2 crystallin are 94% identical in amino acid sequence, and while delta2 crystallin is the duck orthologue of argininosuccinate lyase (ASL) and catalyzes the reversible breakdown of argininosuccinate to arginine and fumarate, the delta1 isoform is enzymatically inactive. The crystal structures of wild type duck delta1 and delta2 crystallin have been solved at 2.2 and 2.3 A resolution, respectively, and the refinement of the turkey delta1 crystallin has been completed. These structures have been compared with two mutant duck delta2 crystallin structures. Conformational changes were observed in two regions of the N-terminal domain with intraspecies differences between the active and inactive isoforms localized to residues 23-32 and both intra- and interspecies differences localized to the loop of residues 74-89. As the residues implicated in the catalytic mechanism of delta2/ASL are all conserved in delta1, the amino acid substitutions in these two regions are hypothesized to be critical for substrate binding. A sulfate anion was found in the active site of duck delta1 crystallin. This anion, which appears to mimic the fumarate moiety of the argininosuccinate substrate, induces a rigid body movement in domain 3 and a conformational change in the loop of residues 280-290, which together would sequester the substrate from the solvent. The duck delta1 crystallin structure suggests that Ser 281, a residue strictly conserved in all members of the superfamily, could be the catalytic acid in the delta2 crystallin/ASL enzymatic mechanism.

PubMed: 11258884
DOI: 10.1021/bi002272k

実験手法

X-RAY DIFFRACTION (2.5 Å)