By searching databases for sequences similar to yeast Lsm12, Albrecht and Lengauer (2004) identified human LSM12. The LSM12 protein has an N-terminal Lsm domain, followed by a putative RNA-binding domain and a C-terminal methyltransferase domain. Hartz (2008) mapped the LSM12 gene to chromosome 17q21.31 based on an alignment of the LSM12 sequence with the genomic sequence.

LSm proteins are a family of RNA-binding proteins found in virtually every cellular organism. LSm is a contraction of 'like Sm', because the first identified members of the LSm protein family were the Sm proteins. LSm proteins are defined by a characteristic three dimensional structure and their assembly into rings of six or seven individual LSm protein molecules.