thioredoxin domain-containing protein 3 (spermatid-specific thioredoxin-2, Sptrx-2, NM23-H8, TXNDC3, NME8, SPTRX2)

Function

• role in final stages of sperm tail maturation in testis &/or epididymis
• role in reduction of disulfide bonds within the sperm FS components
• in vitro, has neither NDP kinase nor reducing activity on disulfide bonds

Structure

• monomer
• contains 3 inactive NDK domains that each lack the active His residue
• contains 1 thioredoxin domain

Compartment

cytoplasm

Expression

• testis-specific
• expressed only in primary spermatocytes & round spermatids
• restricted to spermiogenesis, starting at the pachytene spermatocyte level & peaking at the round & elongating spermatid stage

More general terms

• testis-specific protein

Database

• OMIM: https://mirror.omim.org/entry/607421
• UniProt: http://www.uniprot.org/uniprot/Q8N427.html