From: GenBank-Updates@net.bio.net
Newsgroups: bionet.molbio.genbank.updates
Subject: E.coli folA gene coding for dihydrofolate reductase.
Date: 29 Dec 92 20:55:25 GMT
Distribution: bionet
Checksum: 61959 5

LOCUS       ECOFOLA      1200 bp ds-DNA             BCT       11-DEC-1992
DEFINITION  E.coli folA gene coding for dihydrofolate reductase.
ACCESSION   J01609 J01610 V00276
KEYWORDS    dihydrofolate reductase; folA gene; reductase.
SOURCE      E.coli K12 DNA [1],[2]; strains RS16, RS35, RS50, RS58 & RS89 (all
            originally from K12) DNA [3].
  ORGANISM  Escherichia coli
            Prokaryotae; Gram-negative facultatively anaerobic rods;
            Enterobacteriaceae.
REFERENCE   1  (bases 1 to 1200)
  AUTHORS   Smith,D.R. and Calvo,J.M.
  TITLE     Nucleotide sequence of the E.coli gene coding for dihydrofolate
            reductase
  JOURNAL   Nucleic Acids Res. 8, 2255-2274 (1980)
  STANDARD  full automatic
REFERENCE   2  (bases 494 to 662)
  AUTHORS   Smith,D.R., Rood,J.I., Bird,P.I., Sneddon,M.K., Calvo,J.M. and
            Morrison,J.F.
  TITLE     Amplification and modification of dihydrofolate reductase in
            Escherichia coli: Nucleotide sequence of fol genes from
            mutationally altered plasmids
  JOURNAL   J. Biol. Chem. 257, 9043-9048 (1982)
  STANDARD  full automatic
REFERENCE   3  (bases 494 to 662)
  AUTHORS   Smith,D.R. and Calvo,J.M.
  TITLE     Nucleotide sequence of dihydrofolate reductase genes from
            trimethoprim-resistant mutants of Escherichia coli: Evidence that
            dihydrofolate reductase interacts with another essential gene
            product
  JOURNAL   Mol. Gen. Genet. 187, 72-78 (1982)
  STANDARD  full automatic
COMMENT     [1] compared with PIR data.  [2] and [3] show nucleotide
            alterations in several mutant plasmids which lead to increased
            resistance to the antibiotic trimethoprim in E.coli.  [3] shows
            that their plasmids' increased resistance is due to either a
            mutation in the fol promoter (position 500; 'c' to 't'), which
            increases production of DHFR about 10-fold, or a mutation in the
            structural gene (position 618; 'c' to 't'), which changes a proline
            codon to a serine codon.  [2] and [3] show the fol promoter from
            positions 498 to 508 and 522 to 528.
FEATURES             Location/Qualifiers
     mRNA            534..>1200
                     /note="folA mRNA"
     CDS             558..1037
                     /gene="folA"
                     /note="dihydrofolate reductase"
                     /codon_start=1
                     /translation="MISLIAALAVDRVIGMENAMPWNLPADLAWFKRNTLNKPVIMGR
                     HTWESIGRPLPGRKNIILSSQPGTDDRVTWVKSVDEAIAACGDVPEIMVIGGGRVYEQ
                     FLPKAQKLYLTHIDAEVEGDTHFPDYEPDDWESVFSEFHDADAQNSHSYCFEILERR"
BASE COUNT      306 a    288 c    328 g    278 t
ORIGIN      1 bp upstream of SalI site.
        1 gtcgaccact acattcgttt gcgtcaggca ggcgttgaaa agccggagcg tgaaaccttc
       61 gaaggtgcgc tgaaaaccgg gcgtctggca ctggaaagtt taggtctggg gccgtatgaa
      121 gcgcgagaac gtgccgatgt gttccgccgc tttaatattc agatggtgga agagatggca
      181 atggttgaga acgacaccaa agcccgcgcg gcggtctata aacgcaccag cgcgatgtta
      241 agtgagatca ttaccgagga ccgcgaacat ctgtcattaa ttcaacgaca tggctggcag
      301 ggaaccgaag aaggtaaaca taccggcaac atggcggatg aaccggaaac gaaaccctca
      361 tcctaataaa gagtgacgta aatcacactt tacagctaac tgtttgtttt tgtttcattg
      421 taatgcggcg agtccaggga gagagcgtgg actcgccagc agaatataaa attttcctca
      481 acatcatcct cgcaccagtc gacgacggtt tacgctttac gtatagtggc gacaattttt
      541 tttatcggga aatctcaatg atcagtctga ttgcggcgtt agcggtagat cgcgttatcg
      601 gcatggaaaa cgccatgccg tggaacctgc ctgccgatct cgcctggttt aaacgcaaca
      661 ccttaaataa acccgtgatt atgggccgcc atacctggga atcaatcggt cgtccgttgc
      721 caggacgcaa aaatattatc ctcagcagtc aaccgggtac ggacgatcgc gtaacgtggg
      781 tgaagtcggt ggatgaagcc atcgcggcgt gtggtgacgt accagaaatc atggtgattg
      841 gcggcggtcg cgtttatgaa cagttcttgc caaaagcgca aaaactgtat ctgacgcata
      901 tcgacgcaga agtggaaggc gacacccatt tcccggatta cgagccggat gactgggaat
      961 cggtattcag cgaattccac gatgctgatg cgcagaactc tcacagctat tgctttgaga
     1021 ttctggagcg gcggtaattt tgtatagaat ttacggctag cgccggatgc gacgccggtc
     1081 gcgtcttatc cggccttcct atatcaggct gtgtttaaga cgccgccgct tcggccaaat
     1141 ccttatgccg gttcgacggc tggacaaaat actgtttatc ttcccagcgc aggcaggtta
//