Skip to main navigation Skip to search Skip to main content

Regulation of V‐nitrogenase genes in Anabaena variabilis by RNA processing and by dual repressors

Brenda S. Pratte, Ryan Sheridan, Jessie A. James, Teresa Thiel

Research output: Contribution to journalArticlepeer-review

Abstract

<div class="line" id="line-15"> <i style='color: rgb(28, 29, 30); font-family: "Open Sans", icomoon, sans-serif; font-size: 16px;'> A nabaena variabilis&nbsp; </i> <span style='color: rgb(28, 29, 30); font-family: "Open Sans", icomoon, sans-serif; font-size: 16px;'> &emsp14;ATCC 29413 fixes nitrogen in specialized cells called heterocysts using either a Mo &hyphen;nitrogenase or a V &hyphen;nitrogenase. V &hyphen;nitrogenase structural genes,&nbsp; </span> <i style='color: rgb(28, 29, 30); font-family: "Open Sans", icomoon, sans-serif; font-size: 16px;'> vnfDGK&nbsp; </i> <span style='color: rgb(28, 29, 30); font-family: "Open Sans", icomoon, sans-serif; font-size: 16px;'> , as well as&nbsp; </span> <i style='color: rgb(28, 29, 30); font-family: "Open Sans", icomoon, sans-serif; font-size: 16px;'> vnfEN&nbsp; </i> <span style='color: rgb(28, 29, 30); font-family: "Open Sans", icomoon, sans-serif; font-size: 16px;'> form an operon with&nbsp; </span> <i style='color: rgb(28, 29, 30); font-family: "Open Sans", icomoon, sans-serif; font-size: 16px;'> ava4025&nbsp; </i> <span style='color: rgb(28, 29, 30); font-family: "Open Sans", icomoon, sans-serif; font-size: 16px;'> , located upstream of&nbsp; </span> <i style='color: rgb(28, 29, 30); font-family: "Open Sans", icomoon, sans-serif; font-size: 16px;'> vnfDG&nbsp; </i> <span style='color: rgb(28, 29, 30); font-family: "Open Sans", icomoon, sans-serif; font-size: 16px;'> that is repressed by fixed nitrogen and by Mo . The&nbsp; </span> <i style='color: rgb(28, 29, 30); font-family: "Open Sans", icomoon, sans-serif; font-size: 16px;'> ava4025&nbsp; </i> <span style='color: rgb(28, 29, 30); font-family: "Open Sans", icomoon, sans-serif; font-size: 16px;'> &hyphen; </span> <i style='color: rgb(28, 29, 30); font-family: "Open Sans", icomoon, sans-serif; font-size: 16px;'> vnfDGKEN&nbsp; </i> <span style='color: rgb(28, 29, 30); font-family: "Open Sans", icomoon, sans-serif; font-size: 16px;'> operon is under the control of a Mo &hyphen;repressible promoter located nearly 600&thinsp;bp upstream of&nbsp; </span> <i style='color: rgb(28, 29, 30); font-family: "Open Sans", icomoon, sans-serif; font-size: 16px;'> ava4025&nbsp; </i> <span style='color: rgb(28, 29, 30); font-family: "Open Sans", icomoon, sans-serif; font-size: 16px;'> . Levels of&nbsp; </span> <i style='color: rgb(28, 29, 30); font-family: "Open Sans", icomoon, sans-serif; font-size: 16px;'> vnfDG&nbsp; </i> <span style='color: rgb(28, 29, 30); font-family: "Open Sans", icomoon, sans-serif; font-size: 16px;'> transcript were about 500&hyphen;fold higher than&nbsp; </span> <i style='color: rgb(28, 29, 30); font-family: "Open Sans", icomoon, sans-serif; font-size: 16px;'> ava4025&nbsp; </i> <span style='color: rgb(28, 29, 30); font-family: "Open Sans", icomoon, sans-serif; font-size: 16px;'> , the first gene of the operon. This may be the result of RNA processing at a site 87&thinsp;bp upstream of&nbsp; </span> <i style='color: rgb(28, 29, 30); font-family: "Open Sans", icomoon, sans-serif; font-size: 16px;'> vnfDG&nbsp; </i> <span style='color: rgb(28, 29, 30); font-family: "Open Sans", icomoon, sans-serif; font-size: 16px;'> that was initially identified as the transcription start site. A strain with a deletion in the coding region of&nbsp; </span> <i style='color: rgb(28, 29, 30); font-family: "Open Sans", icomoon, sans-serif; font-size: 16px;'> ava4025&nbsp; </i> <span style='color: rgb(28, 29, 30); font-family: "Open Sans", icomoon, sans-serif; font-size: 16px;'> grew diazotrophically with Mo or with V . Two similar proteins, VnfR 1 and VnfR 2, whose genes are located some distance from the&nbsp; </span> <i style='color: rgb(28, 29, 30); font-family: "Open Sans", icomoon, sans-serif; font-size: 16px;'> ava4025&nbsp; </i> <span style='color: rgb(28, 29, 30); font-family: "Open Sans", icomoon, sans-serif; font-size: 16px;'> &hyphen; </span> <i style='color: rgb(28, 29, 30); font-family: "Open Sans", icomoon, sans-serif; font-size: 16px;'> vnfDGKEN&nbsp; </i> <span style='color: rgb(28, 29, 30); font-family: "Open Sans", icomoon, sans-serif; font-size: 16px;'> operon, each repressed transcription from the&nbsp; </span> <i style='color: rgb(28, 29, 30); font-family: "Open Sans", icomoon, sans-serif; font-size: 16px;'> ava4025&nbsp; </i> <span style='color: rgb(28, 29, 30); font-family: "Open Sans", icomoon, sans-serif; font-size: 16px;'> &hyphen; </span> <i style='color: rgb(28, 29, 30); font-family: "Open Sans", icomoon, sans-serif; font-size: 16px;'> vnfDGKEN&nbsp; </i> <span style='color: rgb(28, 29, 30); font-family: "Open Sans", icomoon, sans-serif; font-size: 16px;'> promoter and a mutant lacking both VnfR 1 and VnfR 2 made the V &hyphen;nitrogenase in the presence of Mo . Overexpression of the V &hyphen;nitrogenase in the double&nbsp; </span> <i style='color: rgb(28, 29, 30); font-family: "Open Sans", icomoon, sans-serif; font-size: 16px;'> vnfR1 vnfR2&nbsp; </i> <span style='color: rgb(28, 29, 30); font-family: "Open Sans", icomoon, sans-serif; font-size: 16px;'> mutant resulted in decreased activity of the Mo &hyphen;nitrogenase. VnfR 1 bound specifically,&nbsp; </span> <i style='color: rgb(28, 29, 30); font-family: "Open Sans", icomoon, sans-serif; font-size: 16px;'> in vitro&nbsp; </i> <span style='color: rgb(28, 29, 30); font-family: "Open Sans", icomoon, sans-serif; font-size: 16px;'> , to a region upstream of the&nbsp; </span> <i style='color: rgb(28, 29, 30); font-family: "Open Sans", icomoon, sans-serif; font-size: 16px;'> ava4025&nbsp; </i> <span style='color: rgb(28, 29, 30); font-family: "Open Sans", icomoon, sans-serif; font-size: 16px;'> promoter. </span></div>
Original languageAmerican English
JournalMolecular Microbiology
Volume88
DOIs
StatePublished - Jan 4 2013

Disciplines

  • Genetics
  • Biology
  • Molecular Biology

Cite this