Halobacterium cutirubrum

Kushwaha, S. C., J. K. G. Kramer, and M. Kates. 1975. Isolation and characterization of C50-carotenoidpigments and other polar isoprenoids from Halobacterium cutirubrum. Biochim. Biophys. Acta. 398 303-314. 

T,2 -tetrahydro-i/, /f-carotene-l,T-diol (144)], which is normally the main pigment of Halobacterium cutirubrum, and lycopene then accumulates. The identification of other compounds that appear in smaller amounts, notably bisanhydrobacterioruberin [2,2 -bis-(3-methylbut-2-enyl)-3,4,3, 4 -tetradehydro-... 

Enzyme Systems. Carotenoid biosynthesis by crude cell-free preparations from Halobacterium cutirubrum 0-carotene), Phycomyces blakesleeanus mutants (/8-carotene), and a Neurospora crassa mutant (phytoene) has been demonstrated. Detailed studies of carotenogenic enzymes from tomato fruit... 

Let us consider first lipid-lipid interaction. Urry et al, showed the existence of a positive CD band at 218 m/x and a negative CD band at about 192 m/z in phosphatidyl choline and phosphatidyl ethanolamine dissolved in trifluoroethanol (86). The 192-m/z band was not characterized in detail, but the 218-m/z band is of such position and shape that the addition of lipid and protein CD bands could produce a composite CD band, and hence an ORD Cotton effect, which is red shifted. As noted by Urry, the 218-m/z CD extremum of lecithin must arise from n — 7T transitions in the fatty acid ester groups. Although the optical activities of solutions of deproteinized membrane phospholipids determined at the same concentration as in the intact membrane are negligibly small, in membranes an ordered array of lipids could greatly enhance rotation. Such an effect could yield information on the nature of lipid-lipid association. This can be tested experimentally. Halobacterium cutirubrum offers a unique system since Kates has shown that the lipids in this extreme halophile contain ether bonds rather than ester bonds (43, 44), Hence, the n — tt transition essential to the CD band at 218 m/z in phospholipids does not exist. Nevertheless, we found that the ORD... 

Fig. 2. The peptidyltransferase center. The structure of the central loop of Domain V of E. coli 23S rRNA is shown. Nucleotides involved in resistance against different inhibitors are indicated. Closed symbols indicate resistance and open symbols protection against chemical modification by bound antibiotic. Mutations that confer resistance to anisomycin in archaea are indicated [87] (Hcu, Halobacterium cutirubrum Hha, H. halobium). The presence of either a G or U at position 2058 in archaea is also indicated. As a consequence of this change archaea are resistant to erythromycin (Hmo, Halococcus morrhuae, Mva, Methanococcus vannielii Tte, Thermoproteus lenax Dmo, Desulfurococcus wofirfo) [29,30,88,90]. Positions where crosslinking to photoreactive derivatives of Phe-tRNA and puromycin have been observed as well as nucleotides protected by bound tRNA are also indicated. Modified from ref [73].

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... 

Kushwaha S. C., Kates M., and Porter J. W. (1976) Enzymatic synthesis of C40 carotenes by cell-free preparation from Halobacterium cutirubrum. Can. J. Biochem. 54, 816-823. 

De M dicis, E. Lalibertd, J.R Vass-Marengo, J. Purification and properties of pyruvate kinase from Halobacterium cutirubrum. Biochim. Bio-phys. Acta, 708, 57-67 (1982)... 

Antimicrobial Activity. The elfamycins antimicrobial specificity and lack of toxicity in animals can be explained in view of species-dependent specificity of elfamycin binding to EF-Tu. Inefficient cellular uptake or the presence of a nomesponding EF-Tu were cited as responsible factors for the natural resistance in Halobacterium cutirubrum (67), iMctobadlhis brevis (68), and in actinomycetes (5,69). The low activity of elfamycins against S. aureus was also attributed to an elfamycin-resistant EF-Tu system (70). However, cross-resistance with other antibacterial agents has not been observed (71). 

Colour bimorphism in the aphid Macrosiphum liriodendri is due mainly to the presence of P,y- and 7,7-carotenes (39) in the green form and to torulene in the pink form. Neo(c/s) isomers of a- and /S-carotene have been isolated from Halobacterium cutirubrum. 

Constit. of the cell membrane of halophi-lic bacteria e.g. Halobacterium cutirubrum, present as phytanylglyceryl deriv. 

Fig. 13. (Upper) ip-NMR spectrum (121.5 MHz) of the purple membrane from Halobacterium cutirubrum obtained with high-power H decoupling at IS C spectral width 125 kHz acquisition time 6 ms recycle time 1 s pulse width 45° decoupler on 4 fts before acquisition and during acquisition but off during remainder of cycle Fourier transform of 16,384 data points after zero iilling. (Lower) Computer simulation of the above in terms of two axially symmetric powder patterns characterized by effective chemical-shift anisotropies of -I-61 and 4-18.5 ppm the angular-independent and -dependent linewidths were 300 and 200 Hz, and 350 and 250 Hz, for the phosphomonoester and phosphodiester, respectively. The broken curves are the powder patterns for the two types of phosphate ester present. From Ekiel et al. (1981).

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