Two histidine residues are essential for catalysis by lecithin retinol acyl transferase

FEBS Letters

Ruiz, Alberto¹  Mondal, Madhu S¹  Hu, Jane¹  Bok, Dean¹  Rando, Robert R¹ 

[1] Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, 45 Shattuck Street, Boston, MA 02115, USA

关键词: Lecithin retinol acyl transferase;    Vitamin A;    Acyl transferase;    Enzyme catalysis;    Enzyme mechanism;    Site-specific mutagenesis;   

DOI  :  10.1016/S0014-5793(00)02428-5

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Lecithin retinol acyl transferase (LRAT) is a novel membrane bound enzyme that catalyzes the formation of retinyl esters from vitamin A and lecithin. The enzyme is both essential for vision and for the general mobilization of vitamin A. The sequence of LRAT defines it as a novel enzyme unrelated to any other protein of known function. LRAT possesses a catalytically essential active site cysteine residue. The enzyme also contains six histidine residues. It is shown here that two of these residues (H57 and H163) are essential for catalysis. A mechanistic hypothesis is presented to account for these observations.

【 授权许可】

Unknown