Turnover of Rubisco (form III)

Value 23 sec^-1
Organism Archaea Archaeoglobus fulgidus
Reference Berg IA. Ecological aspects of the distribution of different autotrophic CO2 fixation pathways. Appl Environ Microbiol. 2011 Mar77(6):1925-36. doi: 10.1128/AEM.02473-10. p.1927 right column 2nd paragraphPubMed ID21216907
Primary Source [63] Kreel, N. E., and F. R. Tabita. 2007. Substitutions at methionine 295 of Archaeoglobus fulgidus ribulose-1,5-bisphosphate carboxylase/oxygenase affect oxygen binding and CO2/O2 specificity. J. Biol. Chem. 282: 1341-1351. DOI: 10.1074/jbc.M609399200PubMed ID17074752
Comments P.1927 right column top paragraph: "The preference of RubisCO for CO2 versus O2 is represented by the specificity factor Ω (Ω = VcKo/VoKc), which is the ratio of the catalytic efficiency (Vmax/Km) for the carboxylase (Vc/Kc) and oxygenase (Vo/Ko) reactions. Up to now, four forms of RubisCO had been recognized, with forms I to III being bona fide ribulose-1,5-bisphosphate carboxylases (ref 101). The fastest of all are the enzymes of Archaea belonging to form III (kcat = 23 s^−1 for Archaeoglobus enzyme), which have, however, unusually high affinity to oxygen (Ω = 4) (primary source)."
Entered by Uri M
ID 112902