Volume 4 Issue 12, December 1997

Competing pathways for the unfolding of barstar pass through different transition states. These results support the new view of folding, but the earlier concepts of defined unfolding pathways and productive intermediates are still needed to interpret the results.

The first mammalian lipoxygenase crystal structure reveals the surprising presence of an N-terminal β-barrel domain that is highly similar to the C-terminal domain of pancreatic Upases. The non-haem iron-containing catalytic domain is a compact version of the soybean lipoxygenase-1 major domain.

The complex process of proenzyme activation for the pepsinogen-like enzymes is clarified by the structure of a unique intermediate.

The flavin mononucleotide (FMN)-binding protein from Desulfovibrio vulgaris (Miyazaki F) is structurally related to a so far hypothetical single-domain precursor of chymotrypsin, with the FMN-binding site coinciding with part of the active site of the protease.

NMR spectroscopy has been used to determine that the dimerization interface of UmuD' in solution is not the homodimer interface originally inferred from crystallographic data. Instead, it resembles an interface that had been hypothesized to be involved in filamentation.

NMR studies of the lymphoproliferation mutant (V238N) of the Fas death domain indicate that helix 3 is unfolded. This local structural change abolishes binding to FADD — a protein that interacts with Fas and also contains a death domain — and causes the accumulation of autoreactive T cells.

Every residue of a putative transmembrane helix in diacylglycerol kinase can be converted to both alanine and leucine while maintaining high specific activity, indicating that some transmembrane helices play a relatively passive role in structure and function.

Here we show how Mg²⁺ and Mn²⁺ function in Escherichia coli phosphoenolpyruvate carboxykinase (PCK) and we propose a general model for the role of binuclear metal clusters in enzyme-catalyzed phosphoryl-transfer reactions.

The 2.0 Å crystal structure of the catalytic domain of human phenylalanine hydroxylase reveals a fold similar to that of tyrosine hydroxylase. It provides the first structural view of where mutations occur and a rationale to explain molecular mechanisms of the enzymatic phenotypes in the autosomal recessive disorder phenylketoneuria.