The R1 domain is found in the MTA1 protein and its homologues. The domain is composed of 4 alpha helices [1]. It has been shown to bind to the RBBP4 protein [1]. The MTA proteins contain a second partial copy of this domain called R2. The R2 domain is matched by this model for some proteins.

1: The structure of the core NuRD repression complex provides insights into its interaction with chromatin. Millard CJ, Varma N, Saleh A, Morris K, Watson PJ, Bottrill AR, Fairall L, Smith CJ, Schwabe JW; Elife. 2016; [Epub ahead of print] PMID:27098840