Regulation of gvp genes encoding gas vesicle proteins in halophilic Archaea
Three gas vesicle gene clusters derived from Halobacterium salinarum (p-vac and c-vac) and Haloferax mediterranei (mc-vac) are used as model systems to study gene regulation in Archaea. An unusual pair of regulatory proteins is involved here, with GvpE acting as transcription activator and GvpD exhibiting a repressing function. Both regulators are able to interact leading to the loss of GvpE and the repression (or turnoff) of the gas vesicle formation. The latter function of GvpD requires a p-loop motif and an arginine-rich region, bR1. Both regulator proteins are differentially expressed from the same gvp transcript in Hfx. mediterranei and Hbt. salinarum PHH4. GvpE appears to recognize a 20-nucleotide activator sequence (UAS) located upstream and adjacent to the TFB-recognition element BRE of the two promoters driving the transcription of the divergently oriented gvpACNO and gvpDEFGHIJKLM gene clusters. The BRE elements of these two promoters are separated by 35 nucleotides only, and the distal portions of the two GvpE-UAS overlap considerably in the center of this region. Mutations here negatively affect the GvpE-induced activities of both gvp promoters, whereas alterations in the proximal UAS portions only affect the activity of the promoter located close by.
KeywordsGvpE activator TFB and TBP Gas vesicle genes
Upstream activator sequence
TATA-box binding protein
Transcription factor B
DNA-dependent RNA polymerase
This work was financially supported by the Deutsche Forschungsgemeinschaft (DFG) as part of the priority programme SPP 1112 “Genome function and gene regulation in Archaea” (Pf 165/8-5). Reinhard Mentele and Friedrich Lottspeich (MPI für Biochemie, Martinsried, Germany) are thanked for the N-terminal sequence determination of PitA, and Katharina Teufel for critical reading of the manuscript.
- Ng WV, Kenney S, Mahairas G, Berquist B, Pan M, Skula H, Lasky S, Baglia N, Thorsson V, Sbrogna J, Swartzell S, Weir D, Hall J, Dahl T, Welti R, Goo YA, Leithauser B, Keller K, Cruz R, Danson MJ, Hough DW, Maddocks DG, Jablonski PE, Krebs MP, Angevine CM, Dale H, Isenbarger TA, Peck RF, Pohlschroder M, Spudich JL, Jung KW, Alam M, Freitas T, Hou S, Daniels CJ, Dennis PP, Omer AD, Ebhardt H, Lowe TM, Liang P, Riley M, Hood L, DasSarma S (2000) Genome sequence of Halobacterium species NRC-1. Proc Natl Acad Sci USA 97:12176–12181PubMedCrossRefGoogle Scholar
- Pfeifer F, Offner S, Krüger K, Englert C (1994) Transformation of halobacteria and investigation of gas vesicle synthesis. Syst Appl Microbiol 16:569–577Google Scholar
- Pfeiffer F, Broicher A, Gillich T, Klee K, Mejia J, Rampp M, Oesterhelt D (2008a) Genome information management and integrated data analysis with HaloLex. Arch Microbiol, this issueGoogle Scholar
- Pfeiffer F, Schuster SC, Broicher A, Falb M, Palm P, Rodewald K, Ruepp A, Soppa J, Tittor J, Oesterhelt D (2008b) Evolution in the laboratory: the genome of Halobacterium salinarum strain RI as compared to strain NRC-1, Genomics, Feb 28; doi: 10.1016/j.ygeno.2008.01.001
- Rodriguez-Valera F, Juez G, Kushner DJ (1983) Halobacterium mediterranei spec. nov., a new carbohydrate-utilizing extreme halophile. Syst Appl Microbiol 4:369–381Google Scholar
- Teufel K, Bleiholder A, Griesbach T, Pfeifer F (2008) Variations in the multiple tbp genes in different Halobacterium salinarum strains and their expression during growth. Arch Microbiol, this issueGoogle Scholar