Ribulose-1,5-bis-phosphate carboxylase/oxygenase (Rubisco) is the rate-limiting carbon fixing enzyme of photosynthesis. Rubisco is a complex of eight large (RbcL) and eight small (RbcS) subunits that requires assembly chaperones. Rubisco accumulation factor 1 (Raf1) is a mayor chaperone involved in Rubisco assembly []. It acts downstream of chaperonin-assisted RbcL folding by stabilizing RbcL antiparallel dimers for assembly into RbcL8 complexes with four Raf1 dimers bound. Raf1 displacement by RbcS results in holoenzyme formation [, ]. It might regulate RuBisCO condensation and decondensation [].
Ribulose-1,5-bis-phosphate carboxylase/oxygenase (Rubisco) is the rate-limiting carbon fixing enzyme of photosynthesis. Rubisco is a complex of eight large (RbcL) and eight small (RbcS) subunits that requires assembly chaperones. Rubisco accumulation factor 1 (Raf1) is a mayor chaperone involved in Rubisco assembly []. It acts downstream of chaperonin-assisted RbcL folding by stabilizing RbcL antiparallel dimers for assembly into RbcL8 complexes with four Raf1 dimers bound. Raf1 displacement by RbcS results in holoenzyme formation [, ]. It might regulate RuBisCO condensation and decondensation [].This protein family includes Raf1 proteins from cyanobacteria.
Leucine-rich repeat protein SHOC2 is a regulatory subunit of protein phosphatase 1 (PP1c) that acts as a M-Ras/MRAS effector and participates in MAPK pathway activation. Upon M-Ras/MRAS activation, it targets PP1c to specifically dephosphorylate the 'Ser-259' inhibitory site of RAF1 kinase and stimulate RAF1 activity at specialised signaling complexes [, ]. In humans, defects in SHOC2 are the cause of Noonan syndrome-like disorder with loose anagen hair (NSLH) []. In Caenorhabditis elegans the homologue is known as Soc2 [].
This is the C-terminal domain, also known as the beta domain, of Rubsico Assembly Chaperone protein (Raf1). Raf1 is necessary for rubisco to catalyze the rate-limiting step of carbon fixation through carboxylating the five-carbon sugar substrate ribulose-1,5-bisphosphate. The beta domains primary function is dimerization, which is critical for Raf1 to achieve the necessary avidity for complex formation with RbcL (the large complex sub-unbit of Rubsico) assembly intermediates. The beta domain is also involved, to a small extent, in binding to RbcL with use of the lustiness near the beta domain's conserved top surface [].
This is the N-terminal alpha helical domain found in Rubisco accumulation factor1 (Raf1). Raf1 from Arabidopsis thaliana consists of an N-terminal alpha-domain, a flexible linker segment and a C-terminal β-sheet domain that mediates dimerization. The α-domains mediate the majority of functionally important contacts with RbcL (Rubisco large subunits) by bracketing each RbcL dimer at the top and bottom. The alpha-domain alone is essentially inactive [].
Protein sprouty homologue 4 (SPRY4) belongs to the sprouty family, whose members are inhibitors of the Ras-ERK pathway downstream of various receptor tyrosine kinases. SPRY4 is a feedback negative regulator of FGFs-induced ERK1/2 signalling. It suppresses Ras-independent ERK activation by binding to Raf1 []. It may function as a tumour suppressor in endometrial adenocarcinoma []. It plays a critical role in developing inflammatory Th17 cells in Th17 cell-driven autoimmune diseases [].
This is helix turn helix domain found in alpha helical region of Rubisco accumulation factor1 (Raf1). Raf1 from Arabidopsis thaliana consists of an N-terminal alpha-domain, a flexible linker segment and a C-terminal β-sheet domain that mediates dimerization. The α-domains mediate the majority of functionally important contacts with RbcL (Rubisco large subunits) by bracketing each RbcL dimer at the top and bottom. The alpha-domain alone is essentially inactive [].
