Previous Article | Next Article ![]()
Journal of Bacteriology, June 2005, p. 4015-4022, Vol. 187, No. 12
0021-9193/05/$08.00+0 doi:10.1128/JB.187.12.4015-4022.2005
Copyright © 2005, American Society for Microbiology. All Rights Reserved.
and
Mechthild Pohlschröder*
Department of Biology, University of Pennsylvania, 201 Leidy Laboratories, 415 South University Ave., Philadelphia, Pennsylvania 19104
Received 30 November 2004/ Accepted 11 March 2005
The targeting of many Sec substrates to the membrane-associated translocation pore requires the cytoplasmic signal recognition particle (SRP). In Eukarya and Bacteria it has been shown that membrane docking of the SRP-substrate complex occurs via the universally conserved SRP receptor (Sr
/ß and FtsY, respectively). While much has been learned about the archaeal SRP in recent years, few studies have examined archaeal Sr
/FtsY homologs. In the present study the FtsY homolog of Haloferax volcanii was characterized in its native host. Disruption of the sole chromosomal copy of ftsY in H. volcanii was possible only under conditions where either the full-length haloarchaeal FtsY or an amino-terminally truncated version of this protein lacking the A domain, was expressed in trans. Subcellular fractionation analysis of H. volcanii ftsY deletion strains expressing either one of the complementing proteins revealed that in addition to a cytoplasmic pool, both proteins cofractionate with the haloarchaeal cytoplasmic membrane. Moreover, membrane localization of the universally conserved SRP subunit SRP54, the key binding partner of FtsY, was detected in both H. volcanii strains. These analyses suggest that the H. volcanii FtsY homolog plays a crucial role but does not require its A domain for haloarchaeal growth.
Present address: Institute for Cancer Research, Fox Chase Cancer Center, Philadelphia, PA 19111.
This article has been cited by other articles:
Copyright © 2009 by the American Society for Microbiology. For an alternate route to Journals.ASM.org, visit: http://intl-journals.asm.org | More Info»