Open AccessIsolation and sequence analysis of the pmi gene encoding phosphomannose isomerase of Streptococcus mutans
Author(s) -
Sato Yutaka,
Yamamoto Yasuhito,
Kizaki Harutoshi,
Kuramitsu Howard K.
Publication year - 1993
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.1574-6968.1993.tb06551.x
Subject(s) - operon , gene , open reading frame , isomerase , nucleic acid sequence , streptococcus mutans , biology , peptide sequence , glucose 6 phosphate isomerase , biochemistry , microbiology and biotechnology , escherichia coli , genetics , chemistry , enzyme , bacteria
A gene encoding a phosphomannose isomerase from Streptococcus mutans GS‐5 was identified immediately downstream from the fructokinase gene, scrK . Nucleotide sequence analysis of this region revealed an open reading frame (ORF) specifying a putative protein of 316 amino acids. The gene cloned in Escherichia coli expressed strong phosphomannose isomerase activity. The deduced amino acid sequence of the pmi gene has no significant similarity with any of the previously reported phosphomannose isomerase enzymes. Insertional inactivation of the upstream gene, scrK , in S. mutans also drastically reduced phosphomannose isomerase activity and the ability of the organism to utilize mannose as a sole carbon source. These results suggest that the S. mutans pmi gene constitutes an operon with the scrK gene.