A small heterodimeric protein complex that is required during early maturation of nascent 40S ribosomal subunits. The complex has endonuclease activity, it interacts with the small ribosomal subunit pre-rRNA and cleave it it to produce the mature 18S (or small ribosomal subunit) rRNA. In S. cerevisiae it is composed of Rcl1p and Bms1p.
small ribosomal subunit maturation complex