2O1H

Naturally occurring mutation of Humna ABO(H) Galactosyltransferase in complex with UDP: GTB/M214T_UDP

2O1H の概要

• エントリーDOI: 10.2210/pdb2o1h/pdb
• 関連するPDBエントリー: 2o1f 2o1g
• 分子名称: ABO glycosyltransferase, MERCURY (II) ION, MANGANESE (II) ION, ... (5 entities in total)
• 機能のキーワード: glycosyltransferase, galactosyltransferase, gtb, blood type subgroup, dxd, transferase
• 由来する生物種: Homo sapiens (human)
• タンパク質・核酸の鎖数: 1
• 化学式量合計: 35958.80

構造登録者

Letts, J.A.,Borisova, S.N.,Evans, S.V. (登録日: 2006-11-28, 公開日: 2007-02-06, 最終更新日: 2023-08-30)

主引用文献

Persson, M.,Letts, J.A.,Hosseini-Maaf, B.,Borisova, S.N.,Palcic, M.M.,Evans, S.V.,Olsson, M.L.
Structural effects of naturally occurring human blood group B galactosyltransferase mutations adjacent to the DXD motif.
J.Biol.Chem., 282:9564-9570, 2007

PubMed Abstract: Human blood group A and B antigens are produced by two closely related glycosyltransferase enzymes. An N-acetylgalactosaminyltransferase (GTA) utilizes UDP-GalNAc to extend H antigen acceptors (Fuc alpha(1-2)Gal beta-OR) producing A antigens, whereas a galactosyltransferase (GTB) utilizes UDP-Gal as a donor to extend H structures producing B antigens. GTA and GTB have a characteristic (211)DVD(213) motif that coordinates to a Mn(2+) ion shown to be critical in donor binding and catalysis. Three GTB mutants, M214V, M214T, and M214R, with alterations adjacent to the (211)DVD(213) motif have been identified in blood banking laboratories. From serological phenotyping, individuals with the M214R mutation show the B(el) variant expressing very low levels of B antigens, whereas those with M214T and M214V mutations give rise to A(weak)B phenotypes. Kinetic analysis of recombinant mutant GTB enzymes revealed that M214R has a 1200-fold decrease in k(cat) compared with wild type GTB. The crystal structure of M214R showed that DVD motif coordination to Mn(2+) was disrupted by Arg-214 causing displacement of the metal by a water molecule. Kinetic characterizations of the M214T and M214V mutants revealed they both had GTA and GTB activity consistent with the serology. The crystal structure of the M214T mutant showed no change in DVD coordination to Mn(2+). Instead a critical residue, Met-266, which is responsible for determining donor specificity, had adopted alternate conformations. The conformation with the highest occupancy opens up the active site to accommodate the larger A-specific donor, UDP-GalNAc, accounting for the dual specificity.

PubMed: 17259183
DOI: 10.1074/jbc.M610998200

実験手法

X-RAY DIFFRACTION (1.67 Å)