Cloning, expression, purification, crystallization and initial crystallographic analysis of the preprotein translocation ATPase SecA fromThermus thermophilus

Abstract
The Thermus thermophilus gene encoding the preprotein translocation ATPase SecA was cloned and expressed and the purified protein was crystallized by the hanging-drop vapour-diffusion technique in two different space groups P31(2)21 (a = b = 168.6, c = 149.8 Å) and P61(5)22 (a = b = 130.9, c = 564.6 Å). The crystals, improved by macroseeding, diffracted to beyond 2.8 and 3.5 Å resolution for the trigonal and hexagonal crystal forms, respectively. Structure determination using the multiple isomorphous replacement method is in progress.