Open AccessThe ether‐cleaving methyltransferase of the strict anaerobe Acetobacterium dehalogenans : analysis of the zinc‐binding site
Author(s) -
Studenik Sandra,
Kreher Sandra,
Diekert Gabriele
Publication year - 2011
Publication title -
fems microbiology letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.899
H-Index - 151
eISSN - 1574-6968
pISSN - 0378-1097
DOI - 10.1111/j.1574-6968.2011.02251.x
Subject(s) - demethylase , zinc , methyltransferase , enzyme , corrinoid , stereochemistry , biochemistry , chemistry , demethylation , binding site , active site , cleavage (geology) , ether , site directed mutagenesis , histidine , ether cleavage , methylation , biology , organic chemistry , mutant , epigenetics , dna methylation , gene expression , gene , paleontology , fracture (geology)
The anaerobic phenyl methyl ether cleavage in acetogenic bacteria is mediated by multicomponent enzyme systems designated O ‐demethylases. Depending on the growth substrate, different O ‐demethylases are induced in Acetobacterium dehalogenans . A vanillate‐ and a veratrol‐ O ‐demethylase of this organism have been described earlier. The methyltransferase I (MT I), a component of this enzyme system, catalyzes the ether cleavage and the transfer of the methyl group to a super‐reduced corrinoid bound to a protein. The MT I of the vanillate‐ and veratrol‐ O ‐demethylase (MT I van and MT I ver ) were found to be zinc‐containing enzymes. By site‐directed mutagenesis, putative zinc ligands were identified, from which the following unique zinc‐binding motifs were derived: E ‐X 14 ‐ E ‐X 20 ‐ H for MT I van and D ‐X 27 ‐ C ‐X 39 ‐ C for MT I ver .