Dataset Information

Cross-linking mass spectrometry and integrative modelling of Methanocaldococcus jannaschii GMP synthetase

ABSTRACT: GMP synthetases are enzymes that catalyze the conversion of XMP to GMP. The two-subunit type GMP synthetases are composed of a glutamine amidotransferase (GATase) subunit that catalyzes the conversion of Gln to Glu and ammonia, and the ATP pyrophosphatase (ATPPase) subunit that catalyzes the formation of AMP-XMP from ATP and XMP. The inactive GATase subunit is allosterically activated by the binding of substrates to the ATPPase subunit. Upon activation, the GATase subunit binds Gln and hydrolyzes it producing ammonia which is tunnelled to the ATPPase subunit. The two subunits form a tight complex to enable domain crosstalk. However, the Methanocaldococcus jannaschii GMP synthetase (MjGMPS) is unique as the GATase (MjGATase) and ATPPase (MjATPPase) subunits interact transiently. Here, we employed enzyme kinetics, X-ray crystallography, cross-linking mass spectrometry (XL-MS) and integrative modelling to understand the mechanistic basis for the various steps in the catalytic cycle of MjGMPS.

INSTRUMENT(S):

ORGANISM(S): Methanocaldococcus Jannaschii Dsm 2661

SUBMITTER: Santosh Shivakumaraswamy