Roles of Mn-catalase and a possible heme peroxidase homologue in protection from oxidative stress in Thermus thermophilus.

Hydrogen peroxide (H2O2) produces hydroxyl radicals that directly attack a variety of biomolecules and cause severe cellular dysfunction. An extremely thermophilic bacterium, Thermus thermophilus HB8, possesses at least three enzymes that can scavenge H2O2: manganese-containing catalase (TTHA0122, MnCAT), a possible peroxiredoxin homologue (TTHA1300), and a possible heme peroxidase (HPX) homologue (TTHA1714). To investigate the roles of these proteins, we attempted to disrupt each of these genes in T.

Very rapid induction of a cold shock protein by temperature downshift in Thermus thermophilus.

A rapid temperature downshift induces the expression of many proteins termed 'cold-induced' proteins. Although some of these proteins are known to participate in metabolism, transcription, translation and protein folding, processes that are affected by cold stress, it has not yet been identified which proteins sense the temperature downshift. Here we analyzed the mRNA expression profiles of genes induced immediately following a temperature downshift in Thermus thermophilus HB8.

Crystal structure of the peptidase domain of Streptococcus ComA, a bifunctional ATP-binding cassette transporter involved in the quorum-sensing pathway.

ComA of Streptococcus is a member of the bacteriocin-associated ATP-binding cassette transporter family and is postulated to be responsible for both the processing of the propeptide ComC and secretion of the mature quorum-sensing signal. The 150-amino acid peptidase domain (PEP) of ComA specifically recognizes an extended region of ComC that is 15 amino acids in length. It has been proposed that an amphipathic alpha-helix formed by the N-terminal leader region of ComC, as well as the Gly-Gly motif at the cleavage site, is critical for the PEP-ComC interaction.

Structure of the minimized alpha/beta-hydrolase fold protein from Thermus thermophilus HB8.

The gene encoding TTHA1544 is a singleton found in the Thermus thermophilus HB8 genome and encodes a 131-amino-acid protein. The crystal structure of TTHA1544 has been determined at 2.0 A resolution by the single-wavelength anomalous dispersion method in order to elucidate its function.

Crystal structure of monofunctional histidinol phosphate phosphatase from Thermus thermophilus HB8.

Monofunctional histidinol phosphate phosphatase from Thermus thermophilus HB8, which catalyzes the dephosphorylation of l-histidinol phosphate, belongs to the PHP family, together with the PHP domain of bacterial DNA polymerase III and family X DNA polymerase. We have determined the structures of the complex with a sulfate ion, the complex with a phosphate ion, and the unliganded form at 1.6, 2.

Structure of a UPF0150-family protein from Thermus thermophilus HB8.

TTHA0281 is a hypothetical protein from Thermus thermophilus HB8 that belongs to an uncharacterized protein family, UPF0150, in the Pfam database and to COG1598 in the National Center for Biotechnology Information Database of Clusters of Orthologous Groups. The X-ray crystal structure of the protein was determined by a multiple-wavelength anomalous dispersion technique and was refined at 1.9 A resolution to a final R factor of 18.