Identification and cloning of the Mycobacterium avium folA gene, required for dihydrofolate reductase activity.
Dihydrofolate reductase is an essential bacterial enzyme necessary for the maintenance of intracellular folate pools in a biochemically active reduced state. In this report, the Mycobacterium avium folA gene was identified by functional genetic complementation, sequenced, and expressed for the first time. It has an open reading frame of 543 bp with a G + C content of 73%. The translated polypeptide sequence shows 58% identity to the consensus sequence of the conserved regions from eight other bacterial dihydrofolate reductases. Recombinant M. avium dihydrofolate reductase was expressed actively in Escherichia coli, and SDS-PAGE analysis revealed a 20 kDa species, agreeable with that predicted from the polypeptide sequence:
Zywno-van Ginkel
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S
Southern Research Institute, Birmingham, AL 35205, USA.
Dooley
T P
TP
Suling
W J
WJ
Barrow
W W
WW
D000595:Amino Acid Sequence; D001483:Base Sequence; D003001:Cloning, Molecular; D017124:Conserved Sequence; D017931:DNA Primers / Q000235:genetics; D004269:DNA, Bacterial / Q000235:genetics; D004926:Escherichia coli / Q000235:genetics; D015870:Gene Expression; D005798:Genes, Bacterial; D008969:Molecular Sequence Data; D008970:Molecular Weight; D015269:Mycobacterium avium Complex / Q000201:enzymology* / Q000235:genetics*; D016366:Open Reading Frames; D016133:Polymerase Chain Reaction; D011994:Recombinant Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D017386:Sequence Homology, Amino Acid; D013762:Tetrahydrofolate Dehydrogenase / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism
D017931:DNA Primers; D004269:DNA, Bacterial; D011994:Recombinant Proteins; D013762:Tetrahydrofolate Dehydrogenase