当前位置： SCI文献检索 > MOLECULAR MICROBIOLOGY期刊下所有文献 > Different residues in periplasmic domains of the CcmC inner membrane protein of Pseudomonas fluorescens ATCC 17400 are critical for cytochrome c biogenesis and pyoverdine-mediated iron uptake.

Different residues in periplasmic domains of the CcmC inner membrane protein of Pseudomonas fluorescens ATCC 17400 are critical for cytochrome c biogenesis and pyoverdine-mediated iron uptake.

Abstract：

:The inner membrane protein CcmC (CytA) of Pseudomonas fluorescens ATCC17400, which has homologues in several bacteria and plant mitochondria, is needed for the biogenesis of cytochrome c. A CcmC-deficient mutant is also compromised in the production and utilization of pyoverdine, the high-affinity fluorescent siderophore. A topological model for CcmC, based on the analysis of alkaline phosphatase fusions, predicts six membrane-spanning regions with three periplasmic loops. Site-directed mutagenesis was used in order to assess the importance of some periplasm-exposed residues, conserved in all CcmC homologues, for cytochrome c biogenesis, and pyoverdine production/utilization. Despite the conservation of the residues His-61, Val-62 and Pro-63 in the first periplasmic loop, and Leu-184, His-185 and Gln-186 in the third periplasmic loop, their simultaneous replacement with Ala only partially affected cytochrome c biogenesis and pyoverdine production/utilization. Simultaneous replacements of residues Trp-115 and Gly-116 in the second periplasmic loop substantially affected pyoverdine production/utilization but not cytochrome c production. An Ala substitution of Asp-127, in the second periplasmic loop, resulted in decreased production of cytochrome c, slower growth in conditions of anaerobiosis and reduced pyoverdine production. On the other hand, a mutation in Trp-126, also in the second periplasmic loop, totally suppressed the production of cytochrome c, whereas it had no effect on the production and utilization of pyoverdine. These results show a differential involvement of amino acid residues in periplasmic domains of CcmC in cytochrome c biogenesis and pyoverdine production/utilization.

journal_name

Mol Microbiol

journal_title

Molecular microbiology

authors

Gaballa A,Baysse C,Koedam N,Muyldermans S,Cornelis P

doi

10.1046/j.1365-2958.1998.01085.x

subject

Has Abstract

pub_date

1998-11-01 00:00:00

pages

547-55

issue

eissn

0950-382X

issn

1365-2958

journal_volume

pub_type

杂志文章

在线工具

Different residues in periplasmic domains of the CcmC inner membrane protein of Pseudomonas fluorescens ATCC 17400 are critical for cytochrome c biogenesis and pyoverdine-mediated iron uptake.