Nucleotide sequences of genes encoding heat-stable and heat-labile glyceraldehyde-3-phosphate dehydrogenases; amino acid sequence and protein thermostability.

The structural gene (gapST) encoding glyceraldehyde-3-phosphate dehydrogenase (GPDH; EC 1.2.1.

Conformational studies on the inactivation of glyceraldehyde-3-phosphate dehydrogenase from the facultative thermophile Bacillus coagulans KU.

Among the various proposals that have been made in attempting to explain the ability of thermophiles to reproduce at high temperatures, there is no doubt that obligate and extreme thermophiles synthesize proteins (and other molecules) that have sufficient intrinsic molecular stability to withstand increased thermal stress. In contrast, the glyceraldehyde-3-phosphate dehydrogenase from the facultative thermophile Bacillus coagulans KU has been shown to be quite thermolabile in vitro. Thermal inactivation is not due to loss of bound NAD+.

Molecular symmetry of glyceraldehyde-3-phosphate dehydrogenase from Bacillus coagulans.

The thermolabile glyceraldehyde-3-phosphate dehydrogenase from the facultative thermophile Bacillus coagulans has a crystallographically exact 2-fold rotation axis of symmetry in one of its orthorhombic crystal forms (Lee et al., 1982). Using various crystallographic techniques, we have now identified this axis to be the molecular R-axis, which is the symmetry axis that relates the two subunits that form each active site of the tetrameric enzyme.