Participates in pre-mRNA U12-dependent splicing, performed by the minor spliceosome which removes U12-type introns. U12-type introns comprises less than 1% of all non-coding sequences. Binds to the 3'- stem-loop of m(7)G-capped U12 snRNA. {ECO:0000269|PubMed:16096647, ECO:0000269|PubMed:19447915, ECO:0000269|PubMed:24480542, ECO:0000269|PubMed:29255062}. This is the function of Ensembl gene identifier ENSG00000185946 (RNPC3, RNA binding region (RNP1, RRM) containing 3).