High-affinity L-arabinose transport operon. Gene product expression and mRNAs

J Mol Biol. 1987 Sep 5;197(1):27-35. doi: 10.1016/0022-2836(87)90606-1.

Abstract

Various portions of the "high-affinity" L-arabinose transport operon were cloned into the plasmid expression vector pKK223-3 and the operon-encoded protein products were identified. The results indicate that three proteins are encoded by this operon. The first is a 33,000 Mr protein that is the product of the promoter-proximal L-arabinose binding protein coding sequence, araF. A 52,000 Mr protein is encoded by sequence 3' to araF and has been assigned to the araG locus. The sequence 3' to araG encodes a 31,000 Mr protein that has been assigned to the araH locus. Both the araG and araH gene products are localized in the membrane fraction of the cell, implying a role in the membrane-associated complex of the high-affinity L-arabinose transport system. Nuclease S1 protection studies indicate that two operon message populations are present in the cell, a full-length operon transcript and a seven- to tenfold more abundant binding protein-specific message. The relative abundance of these two message populations correlates with the differential expression of the binding protein and the membrane-associated proteins of the transport system.

Publication types

  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Arabinose / genetics
  • Arabinose / metabolism*
  • Base Sequence
  • Biological Transport
  • Carrier Proteins
  • Cloning, Molecular
  • Escherichia coli / genetics
  • Escherichia coli Proteins
  • Genes, Bacterial
  • Molecular Sequence Data
  • Operon*
  • Plasmids
  • Protein Biosynthesis
  • RNA, Bacterial
  • RNA, Messenger

Substances

  • AraF protein, E coli
  • Carrier Proteins
  • Escherichia coli Proteins
  • RNA, Bacterial
  • RNA, Messenger
  • Arabinose