5B72

Crystal structure of bovine lactoperoxidase with a broken covalent bond between Glu258 and heme moiety at 1.98 A resolution.

5B72 の概要

• エントリーDOI: 10.2210/pdb5b72/pdb
• 分子名称: Lactoperoxidase, 2-acetamido-2-deoxy-beta-D-glucopyranose-(1-4)-2-acetamido-2-deoxy-beta-D-glucopyranose, SULFATE ION, ... (10 entities in total)
• 機能のキーワード: oxidoreductase
• 由来する生物種: Bos taurus (Bovine)
• タンパク質・核酸の鎖数: 1
• 化学式量合計: 71102.47

構造登録者

Singh, P.K.,Sirohi, H.V.,Kaur, P.,Sharma, S.,Singh, T.P. (登録日: 2016-06-03, 公開日: 2016-07-13, 最終更新日: 2024-11-06)

主引用文献

Singh, P.K.,Sirohi, H.V.,Iqbal, N.,Tiwari, P.,Kaur, P.,Sharma, S.,Singh, T.P.
Structure of bovine lactoperoxidase with a partially linked heme moiety at 1.98 angstrom resolution
Biochim. Biophys. Acta, 1865:329-335, 2016

PubMed Abstract: Lactoperoxidase (LPO) is a member of mammalian heme peroxidase superfamily whose other members are myeloperoxidase (MPO), eosinophil peroxidase (EPO) and thyroid peroxidase (TPO). In these enzymes, the heme moiety is linked to protein through two or three covalent bonds. In the mature LPO, the heme moiety is linked to protein through two ester bonds with highly conserved glutamate and aspartate residues. The previously reported structures of LPO have confirmed the formation of two covalent linkages involving Glu258 and Asp108 with 1-methyl and 5-methyl groups of pyrrole rings A and C respectively. We report here a new form of structure of LPO where the covalent bond between Glu258 and 1-methyl group of pyrrole ring A is present only in a fraction of protein molecules. In this case, the side chain of Glu258 occupies two distinct positions, each of which has a 0.5 occupancy. In one position, it forms a normal ester covalent linkage while in the second position, the side chain of Glu258 is located in the middle of the substrate binding site on the distal heme side. In this position, the atom of the side chain of Glu258 forms several contacts with atoms of other residues and heme moiety. Out of the two observed positions of the side chain of Glu258, the former contributes to the stabilization of heme position and improved catalytic action of LPO while the latter is responsible for the reduced stability of the heme position as well as it blocks the substrate binding site.

PubMed: 27986533
DOI: 10.1016/j.bbapap.2016.12.006

実験手法

X-RAY DIFFRACTION (1.98 Å)