This is the N-terminal domain found in DNA processing protein A (DprA) present in Streptococcus pneumoniae. DprA has recently been discovered to be a transformation-dedicated RecA loader. Transformation is believed to play a major role in genetic plasticity. This domain is known as the sterile alpha motif (SAM) domain. DprAs are able to form a type of dimer through SAM-SAM interactions, also known as N/N interactions [1].

1: Structure-function analysis of pneumococcal DprA protein reveals that dimerization is crucial for loading RecA recombinase onto DNA during transformation. Quevillon-Cheruel S, Campo N, Mirouze N, Mortier-Barriere I, Brooks MA, Boudes M, Durand D, Soulet AL, Lisboa J, Noirot P, Martin B, van Tilbeurgh H, Noirot-Gros MF, Claverys JP, Polard P; Proc Natl Acad Sci U S A. 2012;109:E2466-E2475. PMID:22904190