A new class of cobalamin transport mutants (btuF) provides genetic evidence for a periplasmic binding protein in Salmonella typhimurium.
No periplasmic binding protein has been demonstrated for the ATP-binding cassette (ABC)-type cobalamin transporter BtuCD. New mutations (btuF) are described that affect inner-membrane transport. The BtuF protein has a signal sequence and resembles the periplasmic binding proteins of several other ABC transporters.
Van Bibber
M
M
Department of Biology, University of Utah, Salt Lake City, Utah 84112, USA.
Bradbeer
C
C
Clark
N
N
Roth
J R
JR
D013766:5-Methyltetrahydrofolate-Homocysteine S-Methyltransferase; D018528:ATP-Binding Cassette Transporters / Q000235:genetics* / Q000378:metabolism; D001426:Bacterial Proteins / Q000235:genetics* / Q000378:metabolism; D001483:Base Sequence; D002352:Carrier Proteins / Q000235:genetics* / Q000378:metabolism; D004269:DNA, Bacterial; D004843:Epistasis, Genetic; D029968:Escherichia coli Proteins; D017353:Gene Deletion; D015964:Gene Expression Regulation, Bacterial; D008565:Membrane Proteins / Q000235:genetics* / Q000378:metabolism; D008780:Methyltransferases; D008969:Molecular Sequence Data; D016254:Mutagenesis, Insertional; D009876:Operon; D019897:Periplasm / Q000378:metabolism; D012486:Salmonella typhimurium / Q000235:genetics* / Q000378:metabolism; D017422:Sequence Analysis, DNA; D014805:Vitamin B 12 / Q000378:metabolism*
D018528:ATP-Binding Cassette Transporters; D001426:Bacterial Proteins; C050021:BtuC peptide, E coli; C050022:BtuD peptide, E coli; C121564:BtuF protein, Salmonella typhimurium; D002352:Carrier Proteins; D004269:DNA, Bacterial; D029968:Escherichia coli Proteins; D008565:Membrane Proteins; D008780:Methyltransferases; D013766:5-Methyltetrahydrofolate-Homocysteine S-Methyltransferase; C058170:metE protein, E coli; D014805:Vitamin B 12