Complexity of Gas Vesicle Biogenesis in Halobacterium sp. Strain NRC-1: Identification of Five New Proteins
AUTOR(ES)
Shukla, Hem Dutt
FONTE
American Society for Microbiology
RESUMO
The genome of Halobacterium sp. strain NRC-1 contains a large gene cluster, gvpMLKJIHGFEDACNO, that is both necessary and sufficient for the production of buoyant gas-filled vesicles. Due to the resistance of gas vesicles to solubilization, only the major gas vesicle protein GvpA and a single minor protein, GvpC, were previously detected. Here, we used immunoblotting analysis to probe for the presence of gas vesicle proteins corresponding to five additional gvp gene products. Polyclonal antisera were raised in rabbits against LacZ-GvpF, -GvpJ, and -GvpM fusion proteins and against synthetic 15-amino-acid peptides from GvpG and -L. Immunoblotting analysis was performed on cell lysates of wild-type Halobacterium sp. strain NRC-1, gas vesicle-deficient mutants, and purified gas vesicles, after purification of LacZ fusion antibodies on protein A and β-galactosidase affinity columns. Our results show the presence of five new gas vesicle proteins (GvpF, GvpG, GvpJ, GvpL, and GvpM), bringing the total number of proteins identified in the organelles to seven. Two of the new gas vesicle proteins are similar to GvpA (GvpJ and GvpM), and two proteins contain predicted coiled-coil domains (GvpF and GvpL). GvpL exhibited a multiplet ladder on sodium dodecyl sulfate-polyacrylamide gels indicative of oligomerization and self-assembly. We discuss the possible functions of the newly discovered gas vesicle proteins in biogenesis of these unique prokaryotic flotation organelles.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=400621Documentos Relacionados
- Arsenic Resistance in Halobacterium sp. Strain NRC-1 Examined by Using an Improved Gene Knockout System
- An Archaeal Chromosomal Autonomously Replicating Sequence Element from an Extreme Halophile, Halobacterium sp. Strain NRC-1
- Analysis of insertion mutants reveals two new genes in the pNRC100 gas vesicle gene cluster of Halobacterium halobium.
- The cobY Gene of the Archaeon Halobacterium sp. Strain NRC-1 Is Required for De Novo Cobamide Synthesis
- Comprehensive de novo structure prediction in a systems-biology context for the archaea Halobacterium sp. NRC-1