Is that between pREB7 and pREB8, with 29 of pREB7 (or 38 of pREB8) nucleotides sharing 75 identity. The matching regions range from 100 to 8,500 bp with an average of 1,800 bp. Several plasmids also share a few very large homologous regions ( 10 kbp) but do not share a significant global sequence identity. The internal homology between all A. marina plasmids exceeds that seen between its plasmi
Ith a lambda-phage cI motif are also likely correlated with the extra recA (22, 24). The presence of multiples copies of recA and related enzymes could account for gene duplication and/or integration of foreign genes that would lead to genome expansion. Based on the comparative analysis of many genomes, Konstantinidis et al. (21) hypothesized that species with large genomes may dominate noncompeti
Rently free to specialize their metabolic library.ATP Synthase. One interesting case of the idiosyncratic plasmidgene library in A. marina is the inclusion of a second full set of ATP synthase genes on plasmid pREB4 (AM1 D0157-67). These genes are arranged into a unique operon and the individual proteins do not clearly fit into any of the described families (SI Fig. 5) (25). This unusual operon is
Ed transposable regions for 20 of the genes, significantly lower than the 70 found in Nostoc sp. PCC7120 (2). This is partly because of the vast disparity in transposable elements in the two similarly sized genomes, with nearly 1,300 detected in Nostoc and only 500 in A. marina. Surprisingly, a large number of transposases and integrases in A. marina cluster together in regions with no detectabl
Cyanobacteria and higher plantscontain -carotene as a primary carotenoid found in both PSI and PSII (Fig. 3). In the case of A. marina, -carotene was detected instead of -carotene, and zeaxanthin, an oxidative product of -carotene, was identified as a major carotenoid (4, 13). A similar carotenoid composition has been reported only in Prochlorococcus species that contain atypical, divinyl-Chls, an
Possible that the means of Chl d synthesis could be completely unrelated to anything familiar in chlorophyll chemistry, it is far more likely that an enzyme has been recruited from related pathways. Major sources of interest are the large pool of proteins orthologous to ``Chl degradation'' and aromatic ring breakage,PNAS February 12, 2008 vol. 105 no. 6GENETICSFig. 2. Phylogenetic relationship of
Possible that the means of Chl d synthesis could be completely unrelated to anything familiar in chlorophyll chemistry, it is far more likely that an enzyme has been recruited from related pathways. Major sources of interest are the large pool of proteins orthologous to ``Chl degradation'' and aromatic ring breakage,PNAS February 12, 2008 vol. 105 no. 6GENETICSFig. 2. Phylogenetic relationship of
Tegory (rings 1 and 2), deviation from average GC content (ring 3), and GC skew (ring 4). All plasmids are represented at 10 scale for visualization except pREB9 at 500. Color codes are as follows: turquoise, small-molecule biosynthesis; yellow, central or intermediary metabolism; orange, energy metabolism; red, signal transduction; light blue, DNA metabolism; blue, transcription; purple, protein