Halobacterium salinarium

The CP MAS NMR spectroscopy has been also extensively used for studies of proteins containing retinylidene chromophore like proteorhodopsin or bacteriorhodopsin. Bacteriorhodopsin is a protein component of purple membrane of Halobacterium salinarium.71 7 This protein contains 248 amino acids residues, forming a 7-helix bundle and a retinal chromophore covalently bound to Lys-216 via a Schiff base linkage. It is a light-driven proton pump that translocates protons from the inside to the outside of the cell. After photoisomerization of retinal, the reaction cycle is described by several intermediate states (J, K, L, M, N, O). Between L and M intermediate states, a proton transfer takes place from the protonated Schiff base to the anionic Asp85 at the central part of the protein. In the M and/or N intermediate states, the global conformational changes of the protein backbone take place. 

In this paper, we will describe one of examples, where artificial archaeal glycolipids are applied to the construction of nano-devices containing energy-conversion membrane proteins, by employing the phytanyl-chained glycolipid we have recently developed, i.e., l,3-di-o-phytanyl-2-o- ((3-D-maltotriosyl) glycerol (Mab (Phyt)2, Fig. 1) [16,17] and natural proton pump, bacteriorhodopsin (BR) derived from purple membranes of the extremely halophilic archaeon Halobacterium salinarium S9 [18],... 

Figure 5. Chemical structures of main lipids of purple membranes from Halobacterium salinarium S9 phosphatidylglycerophosphate (PGP), phosphatidylglycerol (PG) and glycolipid sulfate (GLS).

Halobacterium salinarium Methanosarcina frisia Sulfolobus acidocaldarius Sulfolobus solfataricus... 

Figure 8.13 Changes in PolyP content during growth of Halobacterium salinarium on a medium with 2.3 mM of P (Smirnov et al., 2002a) ( ) acid-soluble PolyP ( ) alkali-soluble PolyP.

N. A. Andreeva, T. V. Kulakovskaya and I. S. Kulaev (2000). Inorganic polyphosphates and phos-phohydrolases in Halobacterium salinarium. Mikrobiologiia, 69, 499-505. 

Ballesta, j. P. G., a sparsomydn-resis-tant mutant of Halobacterium salinarium lacks a modification at nudeotide U2603 in the peptidyl transferase centre of 23 S rRNA./. Mol. Biol. 1996, 263, 231-238. 

A complex multi-chromophoric system comprises the purple membrane patches from Halobacterium salinarium. These patches are composed of about 3000 bacter-iorhodopsin proteins. The hyperpolarizability of solubilized monomeric bacterio-rhodopsin was measured by HRS and found to be 2100 x 10 esu at 1064 nm. This high value is due to the presence of a chromophore in the protein, the proto-nated Schiff base of retinal. A purple membrane patch can be treated as a two-dimensional crystal of bacteriorhodopsin proteins, and its structure is known in considerable detail. The analysis of the purple membrane tensor was performed by adding the hyperpolarizabilities of the individual proteins in the purple membrane. From (depolarized) HRS measurements on purple membrane suspensions, the structure of the purple membrane patches, and an average membrane size measured by atomic force microscopy, a fi value of 2200 x 10 esu was calculated for bacteriorhodopsin [22]. The organization of the dipolar protonated Schiff base chro-mophores in the membranes was found to be predominantly octopolar. 

Isoprenylated Carotenoids.—Details of the revised structure of bacterioruberin (38) have been published. Anhydro- and bisanhydro-bacterioruberin [(39) and (40)] were also isolated from Halobacterium salinarium. The latter carotenoid was also... 

The surface glycoprotein of Halobacterium salinarium was the first glycosylated protein detected in prokaryotes [109]. More recent work on the chemical structure of glycopeptides [110-113] and the primary structure of the polypeptide moiety of the surface glycoprotein of Halobacterium halobium - an organism related to Hb. salinarium at the species level - has led to a detailed picture (Fig. 15A) of this molecule. Its main features are ... 

Shioda et al. [43,44] visualized by electron microscopy both regions of naked DNA and of DNA covered with particles in the chromosome of Halobacterium salinarium isolated from gently lysed cells. In a control experiment, they did not detect such particles in E. coli. They also reported the existence of nucleosome-like structures in S. acidocaldarius and methanogens (unpublished results cited in ref. [43]). The size of the particles detected in H. salinarium (9.5 nm) is similar to that of eukaryotic nucleosomes (10.3 nm) however, this putative archaebacterial chromatin is not as regular as eukaryotic chromatin, since not all of the DNA is covered with nucleosomes and since the length of the DNA spacer between the particles is not uniform. In contrast to these results, Bohrmann and coworkers [45] did not visualize nucleosome-like structures in isolated chromosome fibers of Thermoplasma acidophilum. These authors also reported that in situ the nucleoid of T. acidophilum appears to be highly dispersed in the cytoplasm. 

Haloferax (formerly Halobacterium) volcanii, a moderately halophilic species. A close relative of Haloferax volcanii is Haloferax phenon K isolate Aa 2.2 [4]. Halobacterium marismortui, the subject of extensive work on ribosomal proteins, is not closely related to Halobacterium salinarium, instead, it belongs in the genus Haloarcula [2]. 

Several of the purple-membrane-containing extreme halophiles (i.e., Halobacterium salinarium and its close relatives) contain small, high-copy-number plasmids, whose DNA sequences have been determined. The sequences are quite similar, and all have an open reading frame of about 1 kbp and a set of hexanucleotide repeats that may be involved in the maintenance of the plasmid [23-25]. 

As first reported by Joshi et al. [29] in Halobacterium salinarium and Halobacterium cutirubrum, the DNA of halobacteria can be separated into two fractions on the... 

The number of rRNA operons in archaea is always small. Haloferax vol-canii, Methanobacterium thermoautotrophicum and Methanothermus fervidus have two, and Methanobacterium vannielii has four (reviewed by Brown et al. [5]). On the basis of Southern transfers of pulsed field gels, Sanz et al. [106] report that the halophilic archaea have from one to four rRNA operons Haloarcula californiae, 4 Haloferax gibbonsii, 4 Halobacterium halobium NCMB 111, 3 Halobacterium marismortui, 3 Halococcus morrhuae, 2 and Halobacterium salinarium, 1. Bacteria have from one to eleven copies (e.g.. Bacillus subtilis, 11 [107] Escherichia coli, 7 [108], and Mycoplasma pneumoniae, 1 [109]). In Halobacterium halobium, the presence of only one rRNA operon facilitated the isolation of strains with mutated 23S rRNA genes, which are resistant to thiostrepton [110], anisomycin [111] or chloramphenicol [112]. 

Halobacterium halobium (now also known as Halobacterium salinarium) is a halophilic bacterium which lives in concentrated salt solutions. It requires a high NaCl concentration to thrive, growing best in 4.3 M NaCl and becoming nonviable at concentration below -3.0 M. Note that seawater is ordinarily only... 

Rudolph, J. and Oesterhelt, D. (1995). Chemo- and phototaxis require a CheA histidine kinase in the archeon Halobacterium salinarium. EMBO J. 14, 667-673. 

Kupper, J., Marwan, W, Typke, D., Griinbeig, H., Uwer, U., Gluch, M. and Oesterhelt, D. (1994). The flagellar bundle of Halobacterium salinarium is inserted into a distinct polar cap structure./. Bacteriol. 176, 5184—5187. 

Montrone, M., Marwan, W., Grunberg, H., Musseleck, S., Starostzik, C. and Oesterhelt, D. (1993). Sensory rhodopsin-controUed release of the switch factor fumarate in Halobacterium salinarium. Mol. Microbiol. 10, 1077-1085. 

Zhang, W.S., Brooun, A., McCandless, J., Banda, P. and Alam, M. (1996). Signal transduction in the Archaeon Halobacterium salinarium is processed through three subfamilies of 13 soluble and membrane-bound transducer proteins. Proc. Natl Acad. Sci. U.S.A. 93, 4649 54. 

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