Aquifex

Fig. 8. Principal component analysis of the distribution of the predicted folds in bacterial, archaeal, and eukaryotic proteomes. (a) First and second principal components (b) third and fourth principal components. Aae, Aquifex aeolicus Mge, Mycoplasm genitalium Mpn, Mycoplasma pneumoniae Rpr, Rickettsia prowazekii Bbu, Borrelia burgdorferi Bsu, Bacillus subtilis, Hin, Haemophilus influenzae, Hpy, Helicobacter pylori Tma, Thermotoga mari-...

The ribosome recycling factor (RRF) is a 21 kDa protein which is involved in the termination step of protein biosynthesis and catalyses the breakdown of the post termination complex into ribosome, tRNA and mRNA. The solution structure of RRF from the hyperthermophilic bacterium Aquifex aeolicus (7 opt = 85°Q was determined by heteronuclear multidimensional NMR spectroscopy, whereas the backbone NMR assignment was recently carried out for RRF from Themotoga maritima and Thermus thermophilus ... 

A Fe2S2 ferredoxin from the hypertherm ophilic bacterium Aquifex aeolicus, expressed in E. coli, studied by Meyer et al. was shown not to be closely similar to plant or mammalian Fe2S2ferrredoxins.83 The combined EPR, MCD, resonance Raman and Mossbauer study identified an S = state from dithionite reduction with ghvalues of 2.05,1.96 and 1.88. 

Recent phylogenetic analysis showed that ferredoxins most similar to I vaginalis ferredoxins 1-3 are found in Tritrichomonas foetus and in the oomycete Phytophthora soaje. Proteins from G. intestinalis, red algae of genus Cyanidioschyzon, and also from the hyperthermophilic eubacterium Aquifex are also similar to I vaginalis ferredoxins (our unpublished data). 

With more and more crystal structures becoming available, opinions arise that electrostatic interactions are an important factor conferring thermostability on proteins. This opinion is supported by the increasing number of salt bridges found in many thermostable and hyperthermostable proteins (Table 3.3) (Karshikoff, 2001) comparison of the capsid surface residues in lumazine synthase from Bacillus subtilis (mesophilic) and Aquifex aeolicus (hyperthermophilic) show significantly more charged residues than polar residues in the hyperthermophilic protein. 

D-Galacturonic acid has also been found in bacterial polysaccharides.125,126 In several Proteus O-antigens, amino acids are amide-linked to the carboxyl group of a-D-galacturonic127 or glucuronic acid.128 It has been shown that D-galacturonic acid replaces phosphate residues in the lipid A component of the lipopolysaccharide (LPS) from the bacterium Aquifex pyrophilus,129... 

Pandelia ME, Nitschke W, Infossi P, Giudici-Orticoni MT, Bill E, Lubitz W. Characterization of a unique [FeS] cluster in the electron transfer chain of the oxygen tolerant [NiFe] hydrogenase from Aquifex aeolicus. Proc Nat Acad Sci USA. 2011 108(15) 6097—102. 

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