Bacteria sequence features

Fig. 1. (a) Schematic representation of the three types of anoxygenic ([1] and [2]) and oxygenic ([3]) photosynthesis found in plants and bacteria, (b) Phylogenetic tree based on 16S-rRNA sequence comparisons featuring only photo synthetic phyla. 

Cluster Fx was also identified via its EPR spectral features in the RCI photosystem from green sulfur bacteria 31, 32) and the cluster binding motif was subsequently found in the gene sequence 34 ) of the (single) subunit of the homodimeric reaction center core (for a review, see 54, 55)). Whereas the same sequence motif is present in the RCI from heliobacteria (50), no EPR evidence for the presence of an iron-sulfur cluster related to Fx has been obtained. There are, however, indications from time-resolved optical spectroscopy for the involvement of an Fx-type center in electron transfer through the heliobacterial RC 56). 

The 100- to 160-kb chloroplast genomes (Chapter 23, Section E,2) also have many prokaryotic features. They encode 50 proteins as well as the tRNAs and rRNAs. Promoter and terminator sequences resemble those of bacteria and protein sequences are often homologous to those in bacteria. This applies, for example, to the a, (3, and (3 subunits of RNA polymerase.685... 

One of the most prominent features of the 50S subunit is the LI protuberance, seen on the left side in Fig. 29-6A. This protuberance is formed almost entirely by protein LI, which is one of the largest ribosomal proteins. It binds to the 2105-2184 loop in domain V of the 23S RNA (see Fig. 29-14).139 LI has an important regulatory role in bacteria in which it represses translation of its own structural gene by binding to a region in its mRNA close to the Shine-Dalgamo sequence. 

Another common feature of heavy metal P-type ATPases, which has attracted a great deal of interest, is the presence of at least one putative MBS, commonly GMxCxxC, at the N-terminus of these proteins. Interestingly, the number of MBSs increases from 1 or 2 in bacteria and yeast to 3 in Caenorhabditis elegans and 5 or 6 in mammalian CuPAs (Fig. 1). This increase was probably due to the amplification of a portion of coding sequence, as MBSs are highly conserved between various heavy metal transporters, including the conserved leucine residue in the position +8 or +11, isoleucine in the position +8, and phenylalanine in the position... 

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