Volume 10 Issue 4, April 2003

Recent structural studies of acetyl-coenzyme A synthase/carbon monoxide dehydrogenase from Moorella thermoacetica revealed a unique Cu-Ni-[Fe₄-S₄] active site. New data now indicate that active enzyme contains a Ni-Ni-[Fe₄-S₄] site. Novel chemistry is posited for the central Ni atom of this enzyme, which utilizes the toxic gas CO as a catalytic intermediate.

Many different RNA species undergo nucleotide modifications at sites identified by guide small nucleolar ribonucleoprotein (snoRNP) particles. The co-crystal structure of two snoRNP proteins gives valuable clues into the workings of this system.

New structural analysis finds a metal-oxo clusters bound to the iron trafficking protein Fbp. Does this point to a possible strategy for bacterial iron acquisition?

Function analysis of 'insulators' has led to the idea that they comprise two separable and mechanistically distinct insulating activities — one blocking enhancer cross-talk and the other barring heterochromatin spreading. However, results from two recent studies have blurred this mechanistic distinction.

Covalent attachment of ubiquitin-like proteins to other proteins drives numerous important physiological processes. The recent structure of an ubiquitin-like E1 enzyme provides insight into the curious assembly line–like mechanism that initiates all ubiquitin-related protein processing pathways.