Nuclear transition protein 2 (IPR000678)

Short name: TP2

Overlapping homologous superfamilies


Family relationships



In mammals, the second stage of spermatogenesis is characterised by the conversion of nucleosomal chromatin to the compact, nonnucleosomal and transcriptionally inactive form found in the sperm nucleus. This condensation is associated with a double-protein transition. The first transition corresponds to the replacement of histones by several spermatid-specific proteins, also called transition proteins, which are themselves replaced by protamines during the second transition. Nuclear transition protein 2 (TP2) is one of those spermatid-specific proteins. TP2 is a basic, zinc-binding protein [PMID: 1930189] of 116 to 137 amino-acid residues.

Structurally, TP2 consists of three distinct parts, a conserved serine-rich N-terminal domain of about 25 residues, a variable central domain of 20 to 50 residues which contains cysteine residues, and a conserved C-terminal domain of about 70 residues rich in lysines and arginines.

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
PROSITE patterns