Protamine 1 (PRM1)

Protamines are small, arginine-rich, nuclear proteins that replace histones late in the haploid phase of spermatogenesis and are believed essential for sperm head condensation and DNA stabilization. Mice, humans, and certain fish have 2 or more different protamines, whereas the sperm of bull, boar, rat, rabbit, guinea pig, and ram have one form of protamine. The 2 human protamines are denoted P1 and P2 (PRM2).

PRM1 and PRM2 have a single intron, consisting of 91 and 163 bp, respectively. Both genes were found to contain typical TATAA and CAAT boxes at conventional distances from the transcription start points which, by use of primary extension experiments, were assigned to nucleotides -91 and -110 for PRM1 and PRM2, respectively.