Spectroscopic Studies of the EutT Adenosyltransferase from Salmonella enterica: Evidence of a Tetrahedrally Coordinated Divalent Transition Metal Cofactor with Cysteine Ligation.

ABSTRACT: The EutT enzyme from Salmonella enterica, a member of the family of ATP:cobalt(I) corrinoid adenosyltransferase (ACAT) enzymes, requires a divalent transition metal ion for catalysis, with Fe(II) yielding the highest activity. EutT contains a unique cysteine-rich HX₁₁CCX₂C(83) motif (where H and the last C occupy the 67th and 83rd positions, respectively, in the amino acid sequence) not found in other ACATs and employs an unprecedented mechanism for the formation of adenosylcobalamin. Recent kinetic and spectroscopic studies of this enzyme revealed that residues in the HX₁₁CCX₂C(83) motif are required for the tight binding of the divalent metal ion and are critical for the formation of a four-coordinate (4c) cob(II)alamin [Co(II)Cbl] intermediate

SUBMITTER: Pallares IG 

PROVIDER: S-EPMC5241240 | biostudies-literature | 2017 Jan

REPOSITORIES: biostudies-literature