Structural studies show that enzymes have a limited number of unique folds, although structurally related evolved to perform large variety functions. In this review, we focused on containing the low molecular weight thioredoxin reductase (low Mr TrxR) fold. This fold consists two domains, both three-layer ??? sandwich Rossmann-like fold, serving as flavin adenine dinucleotide (FAD) and, in most...

Abstract The vast majority of theoretically possible polypeptide chains do not fold, let alone confer function. Hence, protein evolution from preexisting building blocks has clear potential advantages over ab initio emergence random sequences. In support this view, sequence similarities between different proteins is generally indicative common ancestry, and we collectively refer to such homolog...

Escherichia coli cells from strain fpr, deficient in the soxRS-induced ferredoxin (flavodoxin)-NADP(H) reductase (FPR), display abnormal sensitivity to the bactericidal effects of the superoxide-generating reagent methyl viologen (MV). Neither bacteriostatic effects nor inactivation of oxidant-sensitive hydrolyases could be detected in fpr cells exposed to MV. FPR inactivation did not affect th...

Cells of the VSR751 strain, which was previously isolated as a photoresistant revertant of the visA-deleted (hemH-deleted) strain of Escherichia coli K-12, accumulated uroporphyrin (uro), coproporphyrin (copro) and protoporphyrin IX (proto), but did not accumulate as much protoporphyrin as cells of the parental strain (hemH-deleted). Therefore, we concluded that strain VSR751 must be defective ...