Purification of form L2RubisCO from a marine obligately autotrophic hydrogen-oxidizing bacterium,Hydrogenovibrio marinusstrain MH-110

Ribulose 1,5-bisphosphate carboxylase/oxygenase (RubisCO) was purified from an obligately autotrophic hydrogen-oxidizing bacterium, Hydrogenovibrio marinus MH-110. The protein has a M(r) value of approximately 110,000, and is composed of two identical subunits of 55,000. To our knowledge, the existence of L2-form RubisCO in a chemolithoautotrophic bacterium is first reported in this paper. The N-terminal amino acid sequence determination of the purified enzyme showed high homology with those of the L2-form RubisCO of Rhodospirillum rubrum and the Lx-form RubisCO from Rhodobacter sphaeroides.