Biology:ROP GTPase

From HandWiki
Short description: Plant Protein
ROP Protein Structure
Dark Blue possible binding sites at amino acid locations 13-20, 60-64, and 118-121
Yellow beta sheets
Cyan alpha helices
Red potential phosphorylation site for protein activity regulation; serine residue at amino acid 74
PBD AF-P92978-F1
UniProt [1]

Rho-related GTPases from plants, otherwise known as ROPs, are involved in cell polarity through the regulation of cytoskeleton components like actin and microtubules.[1][2] Unlike mammalian cells, plant cells do not contain heterotrimeric G proteins like Cdc42, Rac, and Rho that are known to regulate cellular polarity.[2]

Structure and Function

ROP proteins are a type of monomeric G proteins found in plants belonging to the Rho family.[1] ROP binding to GTP or GDP determines its activity due to conformational changes within its structure.[1] Within the G-domain of the structure are the G-box motifs G1-5. These motifs are formed during protein folding and are composed of conserved sequences that are responsible for nucleotide and magnesium binding as well as hydrolysis of GTP.[1] Motifs G2 (switch I loop) and G3 (switch II loop) possess distinct conformations depending on GTP binding state.[1] In addition, the G-domain contains a unique and conserved helical domain commonly found in Rho family proteins called αi.[1]

Specific locations within the 3D ROP protein structure, including the amino acids 13-20, 60-64, and 118-121, act as binding sites during protein activity.[3] The serine residue at amino acid 74 has been shown to be a potential protein activity regulation site through phosphorylation.[4]

References