Open AccessLysine is synthesized through the α‐aminoadipate pathway in Thermus thermophilus
Author(s) -
Kosuge Takehide,
Hoshino Takayuki
Publication year - 1998
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.1574-6968.1998.tb13341.x
Subject(s) - thermus thermophilus , auxotrophy , lysine , mutant , biology , biochemistry , open reading frame , saccharomyces cerevisiae , enzyme , gene , escherichia coli , amino acid , peptide sequence
A 3.8‐kb DNA fragment which was able to complement the mutation of a lysine auxotrophic Thermus thermophilus mutant was cloned from T. thermophilus HB27. Sequence analysis of the 3.8‐kb fragment indicated the presence of three open reading frames including a truncated one. The predicted amino acid sequences of two of the three open reading frames showed 55.2% and 45.0% identity with homocitrate synthase and homoaconitate hydratase of Saccharomyces cerevisiae , respectively. These two enzymes act as lysine biosynthetic enzymes through the α‐aminoadipate pathway which has been reported in S. cerevisiae and fungi. Each of the two open reading frames in T. thermophilus was disrupted by integration of the heat‐stable kanamycin nucleotidyltransferase gene. The resulting mutants showed lysine auxotrophy, which could be complemented with α‐aminoadipate but not with diaminopimelate. These results indicate that lysine was synthesized through the α‐aminoadipate pathway and not through the diaminopimelate pathway in T. thermophilus .