The X-ray structure of NccX from Cupriavidus metallidurans 31A illustrates potential dangers of detergent solubilization when generating and interpreting crystal structures of membrane proteins.

ABSTRACT: The x-ray structure of NccX, a type II transmembrane metal sensor, from Cupriavidus metallidurans 31A has been determined at a resolution of 3.12 Å. This was achieved after solubilization by dodecylphosphocholine and purification in the presence of the detergent. NccX crystal structure did not match the model based on the extensively characterized periplasmic domain of its closest homologue CnrX. Instead, the periplasmic domains of NccX appeared collapsed against the hydrophobic transmembrane segments, leading to an aberrant topology incompatible with membrane insertion. This was explained by a detergent-induced redistribution of the hydrophobic interactions among the transmembrane helices and a pair of hydrophobic patches keeping the periplasmic domains together in the native dimer. Molec

SUBMITTER: Ziani W 

PROVIDER: S-EPMC4223319 | biostudies-literature | 2014 Nov

REPOSITORIES: biostudies-literature