Protamine P1 (IPR000221)

Short name: Protamine_P1

Overlapping homologous superfamilies


Family relationships



Protamines are small, highly basic proteins, that substitute for histones in sperm chromatin during the haploid phase of spermatogenesis. They pack sperm DNA into a highly condensed, stable and inactive complex. There are two different types of mammalian protamine, called P1 and P2. P1 has been found in all species studied, while P2 is sometimes absent. There seems to be a single type of avian protamine whose sequence is closely related to that of mammalian P1 [PMID: 2808336].

GO terms

Biological Process

GO:0007283 spermatogenesis

Molecular Function

GO:0003677 DNA binding

Cellular Component

GO:0000786 nucleosome
GO:0005634 nucleus

Contributing signatures

Signatures from InterPro member databases are used to construct an entry.
PROSITE patterns