The sterile alpha motif (SAM) domain is a 70 residue structure found in a large number of proteins involved in diverse processes present throughout the eukaryotes. The SAM domain is known to bind RNA and is arranged in a small five-helix bundle with two large interfaces.There are three isoforms of SAMD3 produced by alternative splicing.The isoform 1 has been chosen as the canonical sequence. All positional information in this entry refers to it. The sequence of isoform 2 differs from the canonical sequence as follows: 219-221: FLW → AGV, 222-520: Missing.And the sequence of isoform 3 differs from the canonical sequence as follows:1-1: M → MRSSKLQSPSPSQEKQGVYLQETAM.