This entry represents the ORC-binding domain of Sir1. Sir1 interacts with the BAH domain of the Orc1 subunit of the origin recognition complex (ORC) resulting in the establishment of silent chromatin at HMR and HML in S.cerevisiae [1]. The amino acids from the ORC interaction region of Sir1 are presented on a conserved, convex surface that forms a complementary interface with the Orc1 BAH domain, critical for transcriptional silencing [1]. Proteins containing this domain also include Y' element ATP-dependent helicase protein 1, which catalyses DNA unwinding and is involved in telomerase-independent telomere maintenance [2].

1: Structural basis of the Sir1-origin recognition complex interaction in transcriptional silencing. Hou Z, Bernstein DA, Fox CA, Keck JL; Proc Natl Acad Sci U S A. 2005;102:8489-8494. PMID:15932939

2: Y'-Help1, a DNA helicase encoded by the yeast subtelomeric Y' element, is induced in survivors defective for telomerase. Yamada M, Hayatsu N, Matsuura A, Ishikawa F; J Biol Chem. 1998;273:33360-33366. PMID:9837911