Roc, or Ras of Complex, proteins are mitochondrial Rho proteins (Miro-1, Swiss:Q8IXI2, and Miro-2, Swiss:Q8IXI1) and atypical Rho GTPases. Full-length proteins have a unique domain organisation, with tandem GTP-binding domains and two EF hand domains (Pfam:PF00036) that may bind calcium. They are also larger than classical small GTPases. It has been proposed that they are involved in mitochondrial homeostasis and apoptosis [1,2,3,4].

1: Roc, a Ras/GTPase domain in complex proteins. Bosgraaf L, Van Haastert PJ; Biochim Biophys Acta. 2003;1643:5-10. PMID:14654223

2: Atypical Rho GTPases have roles in mitochondrial homeostasis and apoptosis. Fransson A, Ruusala A, Aspenstrom P; J Biol Chem 2003;278:6495-6502. PMID:12482879

3: Yeast Miro GTPase, Gem1p, regulates mitochondrial morphology via a novel pathway. Frederick RL, McCaffery JM, Cunningham KW, Okamoto K, Shaw JM; J Cell Biol. 2004;167:87-98. PMID:15479738

4: Structure of the Roc-COR domain tandem of C. tepidum, a prokaryotic homologue of the human LRRK2 Parkinson kinase. Gotthardt K, Weyand M, Kortholt A, Van Haastert PJ, Wittinghofer A; EMBO J. 2008;27:2239-2249. PMID:18650931