Ribulose bisphosphate carboxylase/oxygenase (Rubisco), small subunit and related proteins. Rubisco is a bifunctional enzyme catalyzes the initial steps of two opposing metabolic pathways: photosynthetic carbon fixation and the competing process of photorespiration. Rubisco Form I, present in plants and green algae, is composed of eight large and eight small subunits. The nearly identical small subunits are encoded by a family of nuclear genes. After translation, the small subunits are translocated across the chloroplast membrane, where an N-terminal signal peptide is cleaved off. While the large subunits contain the catalytic activities, it has been shown that the small subunits are important for catalysis by enhancing the catalytic rate through inducing conformational changes in the large subunits. This superfamily also contains specific proteins from cyanobacteria. CcmM plays a role in a CO2 concentrating mechanism, which cyanobacteria need to to overcome the low specificity of their Rubisco and fusions to Rubisco activase, a type of chaperone, which promotes and maintains the catalytic activity of Rubisco. CcmM contains an N-terminal carbonic anhydrase fused to four copies of the Rubisco-small subunit domain

                         10        20        30        40
                 ....*....|....*....|....*....|....*....|....*
gi 62857224    1 MRLTQGTFSFIPDLTDDQITKQVEYAMSKNWSISVEYTEDPHPRN 45
Cdd:CHL00130   1 MRLTQGTFSFLPDLTDQQIEKQIQYAISKGWALNVEWTDDPHPRN 45

ribulose-1,5-bisphosphate carboxylase/oxygenase small subunit; Reviewed

                         10        20        30        40
                 ....*....|....*....|....*....|....*....|....*
gi 62857224    1 MRLTQGTFSFIPDLTDDQITKQVEYAMSKNWSISVEYTEDPHPRN 45
Cdd:CHL00130   1 MRLTQGTFSFLPDLTDQQIEKQIQYAISKGWALNVEWTDDPHPRN 45

Ribulose bisphosphate carboxylase/oxygenase (Rubisco), small subunit. Rubisco is a bifunctional enzyme catalyzes the initial steps of two opposing metabolic pathways: photosynthetic carbon fixation and the competing process of photorespiration. Rubisco Form I, present in plants and green algae, is composed of eight large and eight small subunits. The nearly identical small subunits are encoded by a family of nuclear genes. After translation, the small subunits are translocated across the chloroplast membrane, where an N-terminal signal peptide is cleaved off. While the large subunits contain the catalytic activities, it has been shown that the small subunits are important for catalysis by enhancing the catalytic rate through inducing conformational changes in the large subunits.

                       10        20        30        40
               ....*....|....*....|....*....|....*....|...
gi 62857224  3 LTQGTFSFIPDLTDDQITKQVEYAMSKNWSISVEYTEDPHPRN 45
Cdd:cd03527  1 RTFETFSYLPPLTDEQIAKQIDYIISNGWAPCLEFTEPEHYDN 43

Ribulose bisphosphate carboxylase, small chain; RuBisCO (ribulose-1,5-bisphosphate carboxylase/oxygenase) is a bifunctional enzyme that catalyses both the carboxylation and oxygenation of ribulose-1,5-bisphosphate (RuBP), thus fixing carbon dioxide as the first step of the Calvin cycle. RuBisCO is the major protein in the stroma of chloroplasts, and in higher plants exists as a complex of 8 large and 8 small subunits. The function of the small subunit is unknown. While the large subunit is coded for by a single gene, the small subunit is coded for by several different genes, which are distributed in a tissue specific manner. They are transcriptionally regulated by light receptor phytochrome. which results in RuBisCO being more abundant during the day when it is required.

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|..
gi 62857224     4 TQGTFSFIPDLTDDQITKQVEYAMSKNWSISVEYTEDPHPRN 45
Cdd:smart00961  1 TQETFSYLPPLTDAEIVAQVRYLLAQGYAIGVEHADPRRFRT 42

ribulose-1,5-bisphosphate carboxylase/oxygenase small subunit; Reviewed

                         10        20        30        40
                 ....*....|....*....|....*....|....*....|....*
gi 62857224    1 MRLTQGTFSFIPDLTDDQITKQVEYAMSKNWSISVEYTEDPHPRN 45
Cdd:CHL00130   1 MRLTQGTFSFLPDLTDQQIEKQIQYAISKGWALNVEWTDDPHPRN 45

Ribulose bisphosphate carboxylase/oxygenase (Rubisco), small subunit. Rubisco is a bifunctional enzyme catalyzes the initial steps of two opposing metabolic pathways: photosynthetic carbon fixation and the competing process of photorespiration. Rubisco Form I, present in plants and green algae, is composed of eight large and eight small subunits. The nearly identical small subunits are encoded by a family of nuclear genes. After translation, the small subunits are translocated across the chloroplast membrane, where an N-terminal signal peptide is cleaved off. While the large subunits contain the catalytic activities, it has been shown that the small subunits are important for catalysis by enhancing the catalytic rate through inducing conformational changes in the large subunits.

                       10        20        30        40
               ....*....|....*....|....*....|....*....|...
gi 62857224  3 LTQGTFSFIPDLTDDQITKQVEYAMSKNWSISVEYTEDPHPRN 45
Cdd:cd03527  1 RTFETFSYLPPLTDEQIAKQIDYIISNGWAPCLEFTEPEHYDN 43

Ribulose bisphosphate carboxylase, small chain; RuBisCO (ribulose-1,5-bisphosphate carboxylase/oxygenase) is a bifunctional enzyme that catalyses both the carboxylation and oxygenation of ribulose-1,5-bisphosphate (RuBP), thus fixing carbon dioxide as the first step of the Calvin cycle. RuBisCO is the major protein in the stroma of chloroplasts, and in higher plants exists as a complex of 8 large and 8 small subunits. The function of the small subunit is unknown. While the large subunit is coded for by a single gene, the small subunit is coded for by several different genes, which are distributed in a tissue specific manner. They are transcriptionally regulated by light receptor phytochrome. which results in RuBisCO being more abundant during the day when it is required.

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|..
gi 62857224     4 TQGTFSFIPDLTDDQITKQVEYAMSKNWSISVEYTEDPHPRN 45
Cdd:smart00961  1 TQETFSYLPPLTDAEIVAQVRYLLAQGYAIGVEHADPRRFRT 42