The cyanobacterial homologue of the RNA chaperone Hfq is essential for motility of Synechocystis sp. PCC 6803

Microbiology. 2008 Oct;154(Pt 10):3134-3143. doi: 10.1099/mic.0.2008/020222-0.


The ssr3341 locus was previously suggested to encode an orthologue of the RNA chaperone Hfq in the cyanobacterium Synechocystis sp. strain PCC 6803. Insertional inactivation of this gene resulted in a mutant that was not naturally transformable and exhibited a non-phototactic phenotype compared with the wild-type. The loss of motility was complemented by reintroduction of the wild-type gene, correlated with the re-establishment of type IV pili on the cell surface. Microarray analyses revealed a small set of genes with drastically reduced transcript levels in the knockout mutant compared with the wild-type cells. Among the most strongly affected genes, slr1667, slr1668, slr2015, slr2016 and slr2018 stood out, as they belong to two operons that had previously been shown to be involved in motility, controlled by the cAMP receptor protein SYCRP1. This suggests a link between cAMP signalling, motility and possibly the involvement of RNA-based regulation. This is believed to be the first report demonstrating a functional role of an Hfq orthologue in cyanobacteria, establishing a new factor in the control of motility.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Bacterial Proteins / genetics*
  • Bacterial Proteins / metabolism
  • Blotting, Northern
  • Cyclic AMP / metabolism
  • Fimbriae Proteins / genetics
  • Fimbriae Proteins / metabolism
  • Fimbriae, Bacterial / physiology
  • Gene Expression Regulation, Bacterial
  • Genes, Bacterial
  • Microscopy, Electron, Transmission
  • Molecular Chaperones / genetics*
  • Molecular Chaperones / metabolism
  • Mutagenesis, Insertional
  • Mutation
  • Oligonucleotide Array Sequence Analysis
  • Operon
  • RNA, Bacterial / genetics
  • RNA, Bacterial / metabolism
  • Receptors, Cyclic AMP / genetics
  • Receptors, Cyclic AMP / metabolism
  • Synechocystis / genetics*
  • Synechocystis / metabolism
  • Synechocystis / physiology*
  • Synechocystis / ultrastructure


  • Bacterial Proteins
  • Molecular Chaperones
  • RNA, Bacterial
  • Receptors, Cyclic AMP
  • SYCRP1 protein, Synechocystis
  • Fimbriae Proteins
  • Cyclic AMP

Associated data

  • GEO/GSE10708