RESUMEN
Equine P2 protein has been isolated from horse spinal cord and its structure determined to 2.1 A. Since equine myelin is a viable alternative to bovine tissue for large-scale preparations, characterization of the proteins from equine spinal cord myelin has been initiated. There is an unusually high amount of P2 protein in equine CNS myelin compared with other species. The structure was determined by molecular replacement and subsequently refined to an R value of 0.187 (Rfree=0.233). The structure contains a molecule of the detergent LDAO and HEPES buffer in the binding cavity and is otherwise analogous to other cellular retinol-binding proteins.
Asunto(s)
Proteína P2 de Mielina/química , Médula Espinal/química , Secuencia de Aminoácidos , Animales , Sitios de Unión , Simulación por Computador , Cristalografía por Rayos X/métodos , Detergentes/química , Dimetilaminas/química , HEPES/química , Caballos , Ligandos , Proteínas de Unión al Retinol/química , Alineación de SecuenciaRESUMEN
A typical purple bacterial photosynthetic unit consists of two types of light-harvesting complex (LH1 and LH2) together with a reaction centre. This short review presents a description of the structure of the LH2 complex from Rhodopseudomonas acidophila, which has recently been improved to a resolution of 2.0 A [Papiz et al., J. Mol. Biol. 326 (2003) 1523-1538]. We show how this structure has helped to reveal the details of the various excitation energy transfer events in which it is involved.