Two new mutants of E. coli K12, strains PT9 and PT32 were isolated, that were defective in proline transport. They had no high affinity proline transport activity, but their cytoplasmic membranes retained proline binding activity with altered sensitivity to inhibition by p-chloromercuribenzoate (pCM
Nucleotide sequence of putP, the proline carrier gene of Escherichia coli K12
β Scribed by Nakao, Toshifumi ;Yamato, Ichiro ;Anraku, Yasuhiro
- Publisher
- Springer
- Year
- 1987
- Tongue
- English
- Weight
- 631 KB
- Volume
- 208
- Category
- Article
- ISSN
- 0026-8925
No coin nor oath required. For personal study only.
β¦ Synopsis
The nucleotide sequence of the putP gene coding for the proline carrier in Escherichia coli has been determined and the amino acid sequence of the proline carrier deduced from it. The proline carrier is predicted to consist of 502 amino acids, resulting in a molecular weight of 54,343. The predicted protein is very hydrophobic (70% nonpolar amino acids), and its hydropathy profile suggests that it is composed of 12 hydrophobic segments with a mean length of 24.4 residues/segment. If these segments are assumed to be alpha-helical, the mean length of each domain corresponds to the thickness of the hydrophobic core of the membrane. Potential promoter, catabolite gene activator protein (CAP) binding sites and several palindromic sequences, which might be regulatory regions by the putA gene product, were also found in the 5' flanking region of the postulated putP gene. A typical rho-independent transcription termination signal was found after the terminator codon of the putP gene.
π SIMILAR VOLUMES
The hemB gene of Escherichia coli K12, coding for porphobilinogen synthase (PBG-S; syn., 5-aminolevulinic acid dehydratase, ALA-D), was cloned following insertion of an EcoRI fragment of plasmid F'13 into the mobilizable vector pCR1. The hybrid plasmid carrying the hemB gene was able to complement a
The hemA gene of Escherichia coli K12 was cloned by complementation of a hemA mutant of this organism. Subcloning of the initial 6.0 kb HindIII fragment allowed the isolation of a 1.5 kb NheI-AvaI fragment which retained the ability to complement the hemA mutant. DNA sequencing by the dideoxy chain