The Mechanism of Bidirectional pH Taxis in Bacillus subtilis.

We investigated pH taxis in This bacterium was found to perform bidirectional taxis in response to external pH gradients, enabling it to preferentially migrate to neutral environments. We next investigated the chemoreceptors involved in sensing pH gradients. We identified four chemoreceptors involved in sensing pH: McpA and TlpA for sensing acidic environments and McpB and TlpB for sensing alkaline ones.

Ancient Regulatory Role of Lysine Acetylation in Central Metabolism.

Lysine acetylation is a common protein post-translational modification in bacteria and eukaryotes. Unlike phosphorylation, whose functional role in signaling has been established, it is unclear what regulatory mechanism acetylation plays and whether it is conserved across evolution. By performing a proteomic analysis of 48 phylogenetically distant bacteria, we discovered conserved acetylation sites on catalytically essential lysine residues that are invariant throughout evolution.

Exploiting fine-scale genetic and physiological variation of closely related microbes to reveal unknown enzyme functions.

Polysaccharide degradation by marine microbes represents one of the largest and most rapid heterotrophic transformations of organic matter in the environment. Microbes employ systems of complementary carbohydrate-specific enzymes to deconstruct algal or plant polysaccharides (glycans) into monosaccharides. Because of the high diversity of glycan substrates, the functions of these enzymes are often difficult to establish.

Elucidation of the multiple roles of CheD in Bacillus subtilis chemotaxis.

Chemotaxis by Bacillus subtilis requires the CheD protein for proper function. In a cheD mutant when McpB was the sole chemoreceptor in B. subtilis, chemotaxis to asparagine was quite good.

Common effects of acidic activators on large-scale chromatin structure and transcription.

Large-scale chromatin decondensation has been observed after the targeting of certain acidic activators to heterochromatic chromatin domains. Acidic activators are often modular, with two or more separable transcriptional activation domains. Whether these smaller regions are sufficient for all functions of the activators has not been demonstrated.