Crystallization and preliminary X-ray crystallographic analysis of the receptor-uncoupled mutant of Gαi1

摘要

In order to understand the molecular mechanisms by which G-protein-coupled receptors (GPCRs) activate G proteins, the K349P mutant of Gαi1 (K349P), which is unable to couple to the muscarinic acetylcholine receptor, was prepared and its crystals were grown along with those of wild-type Gαi1 protein (WT). The two proteins were crystallized under almost identical conditions, thus enabling a detailed structural comparison. The crystallization conditions performed well irrespective of the identity of the bound nucleotide (GDP or GTPγS) and the crystals diffracted to resolutions of 2.2 Å (WT·GDP), 2.8 Å (WT·GTPγS), 2.6 Å (K349P·GDP) and 3.2 Å (K349P·GTPγS).