Matrin 3(MATR3) is localized in the nuclear matrix. It may play a role in transcription or may interact with other nuclear matrix proteins to form the internal fibrogranular network. Two transcript variants encoding the same protein have been identified for this gene.

The deduced 845-amino acid protein has a calculated molecular mass of approximately 95 kD. Its primary structure consists of 33% charged residues and is generally hydrophilic. Like the lamins, matrin-3 has a positively charged N terminus that contains a large number of amino acids with free hydroxyl groups. A highly acidic domain near the C terminus, in which 32% of the amino acids are acidic, is a characteristic found in other nuclear proteins.