Showing papers by "Javier Seravalli published in 2008"
TL;DR: A 2.5 A resolution structure of xenon-pressurized mtCODH/ACS is reported and the nature of gaseous cavities within this enzyme are examined to study channel design principles, as well as consider the conformational flexibility of an enzyme that contains a cavity through its center.
Abstract: A fascinating feature of some bifunctional enzymes is the presence of an internal channel or tunnel to connect the multiple active sites. A channel can allow for a reaction intermediate generated at one active site to be used as a substrate at a second active site, without the need for the intermediate to leave the safety of the protein matrix. One such bifunctional enzyme is carbon monoxide dehydrogenase/acetyl-CoA synthase from Moorella thermoacetica (mtCODH/ACS). A key player in the global carbon cycle, CODH/ACS uses a Ni−Fe−S center called the C-cluster to reduce carbon dioxide to carbon monoxide and uses a second Ni−Fe−S center, called the A-cluster, to assemble acetyl-CoA from a methyl group, coenzyme A, and C-cluster-generated CO. mtCODH/ACS has been proposed to contain one of the longest enzyme channels (138 A long) to allow for intermolecular CO transport. Here, we report a 2.5 A resolution structure of xenon-pressurized mtCODH/ACS and examine the nature of gaseous cavities within this enzyme. We...
106 citations
TL;DR: P pulse-chase studies demonstrate that CoA is the last substrate to bind and that CO and the methyl group bind randomly as the first substrate in acetyl-CoA synthesis.
50 citations