The Crystal Structure of Holo-glyceraldehyde-3-phosphate Dehydrogenase from the Hyperthermophilic BacteriumThermotoga maritimaat 2.5 Å Resolution

Tetrameric triosephosphate isomerase from hyperthermophilic Archaea

“…The observation that especially the subunit contacts are intensified by a strikin! ; increase in ion pairs (as found for the malate dehydrogenas,," from Thermusflavus [6] and the glutamate dehydrogenase fr~,m Pyrococcusfuriosus [5]) and hydrophobic interactions (as reported for the glyceraldehyde-3-phosphate dehydrogenase fr~,m Thermotoga maritima [4]) suggests that the subunit con-*(orresponding author. Fax: (49) (201) 183 2529.…”

“…From the suggested importance of the intersubunit contacts for thermostabilization, as deduced from experimental and comparative studies on various oligomeric enzymes [4][5][6][7], one should expect that the benefit of the higher association state resides in an increase of protein thermostability. The observation that the preference of a higher association state does not generally apply (or even countercurrent trends occur, as shown in the case of the enolases [25]) indicates that the advantage of association is limited by functional and/or structural restraints.…”

“…From the various studies different featu,'es have been discussed as responsible for the increased conformational stability at all three levels of protein structure (c~,re region and secondary structure elements, interactions between domains and subunits): e.g. reduction of solvent acce~sible area and increase in the fraction of buried atoms [1], st~bilization of a-helices, strengthening of polypeptide chain teTmini and loops [2], shortening of loops [3], increase of ion bridges and hydrophobic interactions [4][5][6]. The observation that especially the subunit contacts are intensified by a strikin!…”

Structure of Holo-glyceraldehyde-3-phosphate Dehydrogenase fromPalinurus versicolorRefined at 2 Å Resolution

“…For structure comparison, four GAPDH structures with resolutions higher than 2.5 A Ê in the Protein Data Bank were used. They are BS (entry 1GD1; Skarzynski et al, 1987), TM (entry 1HDG; Korndorfer et al, 1995), TA (entry 1CER; Tanner et al, 1996), and EC (entry 1GAD; Due  e et al, 1996). Of these, EC is mesophilic and the rest are thermophilic.…”

“…GAPDH structures were ®rst determined for the enzymes from lobster (Homarus americanus) muscle, and then for that from the moderate thermophile Bacillus stearothermophilus in several conformational states (Moras et al, 1975;Murthy et al, 1980;Skarzynski et al, 1987;Skarzynski & Wonacott, 1988). In addition, there are several crystallographic investigations for enzymes from other species such as human muscle (Mercer et al, 1976), Bacillus coagulans (Grif®th et al, 1983), Trypanosoma brucei (Vellieux et al, 1993), Thermotoga maritima (Korndorfer et al, 1995), Thermus aquaticus (Tanner et al, 1996), and E. coli (Due  e et al, 1996). These structural investigations provide important information on the folding, catalysis, allosterism mechanism, as well as the thermal stability of this important enzyme.…”