This domain, consisting of the distinct N-terminal PRY subdomain followed by the SPRY subdomain, is found at the C-terminus of TRIM69 and TRIM proteins NF7 and bloodthirsty (bty). TRIM69 is a novel testis E3 ubiquitin ligase that may function to ubiquitinate its particular substrates during spermatogenesis. In humans, TRIM69 localizes in the cytoplasm and nucleus, and requires an intact RING finger domain to function. TRIM protein NF7, which also contains a chromodomain (CHD) at the N-terminus and an RFP (Ret finger protein)-like domain at the C-terminus, is required for its association with transcriptional units of RNA polymerase II which is mediated by a trimeric B box. In Xenopus oocyte, xNF7 has been identified as a nuclear microtubule-associated protein (MAP) whose microtubule-bundling activity, but not E3-ligase activity, contributes to microtubule organization and spindle integrity. Bloodthirsty (bty) is a novel gene identified in zebrafish and has been shown to likely play a role in in regulation of the terminal steps of erythropoiesis.