Availability of porphobilinogen controls appearance of porphobilinogen deaminase activity in Escherichia coli K-12.
AUTOR(ES)
Umanoff, H
RESUMO
A hemin-permeable hemB mutant had no 5-aminolevulinate dehydratase (ALA D) and extremely low porphobilinogen deaminase (PBG D) activity. When the structural gene for hemB was introduced into this strain on a single-copy plasmid, both activities were observed. When the mutant was grown on PBG, normal PBG D activity was observed. Moreover, a hemA mutant had little or no PBG D activity unless it was grown on ALA or PBG. Neither hemin nor PBG affected the level of PBG D protein produced from in vitro transcription and translation of a plasmid harboring the hemC gene as an insert. We conclude that, in Escherichia coli, PBG availability controls the activity of PBG D at some posttranscriptional level.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=211550Documentos Relacionados
- A novel L-serine deaminase activity in Escherichia coli K-12.
- Mapping of the gene for cytidine deaminase (cdd) in Escherichia coli K-12.
- Positive control in the D-serine deaminase system of Escherichia coli K-12.
- Nucleotide sequence of the hemC locus encoding porphobilinogen deaminase of Escherichia coli K12.
- In vitro and in vivo activation of L-serine deaminase in Escherichia coli K-12.
