Contrin (MSY2 in mouse) and YB-2 (MSY3/4 in mouse) belong to the Y-box family of multifunctional proteins that regulate both transcription and translation.Y-box proteins interact with a wide variety of nucleic acid structures to act as transcription factors and mRNA masking proteins. The modular structure of Y-box proteins includes a highly conserved N-terminal cold-shock domain (CSD, equivalent to the bacterial cold-shock proteins) and four basic C-terminal domains containing arginine clusters and aromatic residues. MSY2 (Contrin) is a expressed in testis and ovary, where it may repress translation of parental mRNA. The gene encoding human Contrin maps to chromosome 17p11.2-13.1. MSY3/4 (YB-2) is also known as DNA binding protein A and is highly expressed in testis, heart and muscle. Contrin and YB-2 bind to the consensus sequence 5'-UCCAUCA-3' contained in the Y-box element .