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Lipoylation of H‐protein of the glycine cleavage system The effect of site‐directed mutagenesis of amino acid residues around the lipoyllysine residue on the lipoate attachment
Author(s) -
Fujiwara Kazuko,
Okamura-Ikeda Kazuko,
Motokawa Yutaro
Publication year - 1991
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/0014-5793(91)81164-4
Subject(s) - lipoic acid , biochemistry , residue (chemistry) , glycine cleavage system , site directed mutagenesis , amino acid , mutagenesis , chemistry , active site , glycine , amino acid residue , enzyme , acyltransferases , stereochemistry , peptide sequence , biosynthesis , mutant , gene , antioxidant
H‐protein of the glycine cleavage system has lipoic acid on the Lys 59 residue. Comparison of amino acid sequences around the lipoate attachment site of H‐proteins from various sources and acyltransferases of α‐ keto acid dehydrogenase complexes indicated that Gly 43 , Glu 56 , Glu 63 and Gly 70 of bovine H‐protein are highly conserved among these proteins. Modification of these conserved residues by site‐directed mutagenesis indicated that Glu 56 and Gly 70 are important for the lipoylation of H‐protein and suggested that the proper conformation around the lipoic acid attachment site is required for the association of H‐protein to the enzyme responsible for the lipoylation.