DNA polymerase eta (Pol eta) functions in the error-free bypass of UV-induced DNA lesions, and a defect in Pol eta in humans causes the cancer-prone syndrome, the variant form of xeroderma pigmentosum. Both yeast and human Pol eta replicate through a cis-syn thymine-thymine dimer (TT dimer) by inserting two As opposite the two Ts of the dimer. Pol eta, however, is a low-fidelity enzyme, and it ...

Exotoxin A (ETA) inhibits protein synthesis in cells by a process that involves receptor-mediated endocytosis and the transport of a 37-kDa proteolytic fragment across a membrane into the cytoplasm. The fragment is apparently generated by the endoprotease furin after the toxin has been endocytosed. Cleavage of ETA by furin requires a low pH in vitro, and presumably also in vivo. Drugs that rais...

SUMMARY The Evolutionary Trace Annotation (ETA) Server predicts enzymatic activity. ETA starts with a structure of unknown function, such as those from structural genomics, and with no prior knowledge of its mechanism uses the phylogenetic Evolutionary Trace (ET) method to extract key functional residues and propose a function-associated 3D motif, called a 3D template. ETA then searches previou...

A DNA lesion created by oxidative stress is 7,8-dihydro-8-oxo-guanine (8-oxoG). Because 8-oxoG can mispair with adenine during DNA synthesis, it is of interest to understand the efficiency and fidelity of 8-oxoG bypass by DNA polymerases. We quantify bypass parameters for two DNA polymerases implicated in 8-oxoG bypass, Pols delta and eta. Yeast Pol delta and yeast Pol eta both bypass 8-oxoG an...

It has long been argued that the notion of substitution in the λ-calculus needs to be made explicit. This resulted in many calculi have been developed in which the computational steps of the substitution operation involved in β-contractions have been atomised. In contrast to the great variety of developments for making explicit formalisations of the Beta rule, less work has been done for giving...

Human DNA polymerase eta (pol eta) can replicate across UV-induced pyrimidine dimers, and defects in the gene encoding pol eta result in a syndrome called xeroderma pigmentosum variant (XP-V). XP-V patients are prone to the development of cancer in sun-exposed areas, and cells derived from XP-V patients demonstrate increased sensitivity to UV radiation and a higher mutation rate compared with w...

The role of Pseudomonas aeruginosa exotoxin A (ETA) as a virulence factor in the lung infections of cystic fibrosis (CF) patients is not well understood. Transcript-accumulation studies of bacterial populations in sputum reveal high levels of transcription of toxA, which encodes ETA, in some patients with CF. However, in general, tissue damage in the lungs of patients with CF does not seem to b...