Form 1 Rubisco Research Paper

Rubisco exists in four forms. Form I Rubisco is a hexadecamer, which is repeated four times in the basic structural motif, a dimer of large subunits, to form a catalytic core of L8, with small subunits on the top and bottom of this core (L8S8).14–16 Form II Rubisco is a simple dimer of large subunits, ranging from L2-8, sharing 25–30% identity to the L subunits of Form I Rubisco. This structure is similar to the structure of the basic dimer of the Form I Rubisco despite some differences in catalytic properties.16,17 Form III Rubisco is the dimers of large subunits in either an L2 or (L2)5 and is found only in archaea. Form IV Rubisco (Rubisco-like Protein) is a simple dimer of large subunits (L2) that do not use CO2 as a major carbon source.18,19 …show more content…
Cyanobacteria, one of the photosynthetic bacteria, consist of chlorophyll, whereas the other forms of photosynthetic bacteria consist of bacteriochlorophyll. Although bacteriochlorophyll is similar to chlorophyll, it absorbs light of a broad wavelength than chlorophyll. In addition, because bacteria that contain bacteriochlorophyll do not use water as the electron donor, they do not produce oxygen. Bacteria such as purple and green sulfur bacteria use sulfur as the electron acceptor. Purple nonsulfur bacteria constitute a nontaxonomic group of versatile organisms, in which most of them can grow as photoheterotrophs, photoautotrophs, or chemoheterotrophs – switching from one mode to another depending on conditions such as: degree of anaerobiosis and availability of carbon source (CO2 for autotrophic growth, organic compounds for heterotrophic growth) and light (needed for phototrophic growth). These bacteria do not use hydrogen sulfide as an electron donor when growth occurs photoautotrophically. Because H2S is toxic at higher concentrations, this bacteria can use H2 and low concentration of sulfide such as S-, S2O3-, and …show more content…
The Calvin cycle enzymes are located in two separated operons. The cbbI operon comprises the structural genes that encode Calvin cycle enzymes: fructose 1,6-bisphosphatase (cbbF1, ~37kDa), phosphoribulokinase (prkA, ~40kDa), fructose-bisphosphate aldolase (cfxA, ~31kDa), Form I ribulose bisphosphate carboxylase/oxygenase (Rubisco) large subunit (cbbL, ~54kDa), and Form I ribulose bisphosphate carboxylase/oxygenase (Rubisco) small subunit (cbbS, ~14kDa) (L8S8). The cbbII operon consists of the structural genes that encode Calvin cycle enzymes: fructose 1,6-bisphosphatase (fbpB, ~37kDa), phosphoribulokinase (prkB, ~32kDa), transketolase (tklB, ~72kDa), glyceraldehyde-3-phosphate dehydrogenase (gapB, ~37kDa), fructose bisphosphate aldolase (cfxB, ~39kDa), and ribulose 1,5-bisphosphate carboxylase/oxygenase (Rubisco) large subunit (rbpL, ~51kDa)