Structure of aldolase from Thermus thermophilus HB8 showing the contribution of oligomeric state to thermostability.
2-Deoxyribose-5-phosphate aldolase catalyzes a reversible aldol condensation of two aldehydes via formation of a covalent Schiff-base intermediate at the active lysine residue. The crystal structure of 2-deoxyribose-5-phosphate aldolase from Thermus thermophilus HB8 has been determined with and without the substrate at atomic resolution. This enzyme, which has a unique homotetramer structure, has been compared with the previously reported crystal structures of two orthologues from Escherichia coli and Aeropyrum pernix. In contrast to the similar alpha/beta-barrel fold of the monomers, substantial quaternary structural differences are observed between these three enzymes. Further comparison of the subunit-subunit interface areas of these aldolases showed a clear positive correlation between the interface area and the living temperature of the source organism. From these results, it is concluded that the oligomeric state of 2-deoxyribose-5-phosphate aldolase is important for the thermostability and not for the catalytic function.
Lokanath
Neratur K
NK
Highthroughput Factory, RIKEN Harima Institute at SPring-8, 1-1-1 Kouto, Mikazuki-cho, Sayo-gun, Hyogo 679-5148, Japan.
Shiromizu
Ikuya
I
Ohshima
Noriyasu
N
Nodake
Yuichi
Y
Sugahara
Mitsuaki
M
Yokoyama
Shigeyuki
S
Kuramitsu
Seiki
S
Miyano
Masashi
M
Kunishima
Naoki
N
D041522:Aeropyrum / Q000201:enzymology; D000446:Aldehyde-Lyases / Q000737:chemistry*; D000595:Amino Acid Sequence; D002384:Catalysis; D018360:Crystallography, X-Ray; D019281:Dimerization; D004926:Escherichia coli / Q000201:enzymology; D005634:Fructose-Bisphosphate Aldolase / Q000737:chemistry*; D006358:Hot Temperature; D007700:Kinetics; D008024:Ligands; D008956:Models, Chemical; D008958:Models, Molecular; D008969:Molecular Sequence Data; D011487:Protein Conformation; D020836:Protein Structure, Quaternary; D017433:Protein Structure, Secondary; D017434:Protein Structure, Tertiary; D017386:Sequence Homology, Amino Acid; D013696:Temperature; D016963:Thermus thermophilus / Q000201:enzymology*
D008024:Ligands; D000446:Aldehyde-Lyases; D005634:Fructose-Bisphosphate Aldolase; C020019:deoxyribose-phosphate aldolase