avermitilis and S. coelicolor). The second trend is that the

groups with potentially linear chromosomes generally have chromosomes of a larger size, most being larger than 6.5 Mb. This suggests that if you need to increase your see more chromosome size evolutionarily, linearity may be an advantage. “
“Lipoteichoic acid (LTA) is a zwitterionic polymer found in the cell wall of many Gram-positive bacteria. A widespread and one of the best-studied forms of LTA consists of a polyglycerolphosphate (PGP) chain that is tethered to the membrane via a glycolipid anchor. In this review, we will summarize our current understanding of the enzymes involved in glycolipid and PGP backbone synthesis in a variety of different Gram-positive bacteria. The recent identification of key LTA synthesis proteins allowed the construction and analysis of mutant strains with defined defects in glycolipid or backbone synthesis. Using these strains, new information on the functions of LTA for bacterial growth, physiology and during developmental processes was gained and will be discussed. Furthermore, we will reintroduce the idea that LTA remains in close proximity to the bacterial membrane for its function during bacterial growth rather than as a surface-exposed structure. “
“The Gram-negative bacterium

Pseudomonas sp. strain ADP is the best-characterized organism able to mineralize the s-triazine herbicide learn more atrazine. This organism has been the subject of extensive biochemical and genetic characterization that has led to its use in bioremediation programs aimed at the decontamination of atrazine-polluted sites. Here, we focus on the recent advances in the understanding of the mechanisms of genetic regulation operating on the atrazine-degradative genes. The Pseudomonas sp. strain ADP atrazine-degradation pathway is encoded by two sets of genes: the constitutively expressed atzA, atzB and atzC, and the strongly regulated atzDEF operon. A complex

cascade-like circuit is responsible through for the integrated regulation of atzDEF expression in response to nitrogen availability and cyanuric acid. Mechanistic studies have revealed several unusual traits, such as the upstream activating sequence-independent regulation and repression by competition with σ54-RNA polymerase for DNA binding occurring at the σ54-dependent PatzR promoter, and the dual mechanism of transcriptional regulation of the PatzDEF promoter by the LysR-type regulator AtzR in response to two dissimilar signals. These findings have provided new insights into the regulation of the atrazine-biodegradative pathway that are also relevant to widespread bacterial regulatory phenomena, such as global nitrogen control and transcriptional activation by LysR-type transcriptional regulators.