TABLE 1.

Additional nonribosomal components of the SSU processome

ProteinAliasGene productMol wt (103)Essential?Homolog (GenBank no. and/or % homology)Motif and/or commentbReferences
Utp18YJL069c66.3YesCGI-48 (25)WD repeats, interacts with Utp21; one peptide in purification4, 12
Noc4YPR144c63.5YesMGC3162 (31)Noc domain and ribosome biogenesis8, 9, 12, 24, 29
Utp20YBL004w287YesDRIMa (NP05531 8.1; 23)HEAT repeats and homolog of DRIM8, 9, 12, 33, 34
Utp21YLR409c105YesTA-WDRP (NP644810.1; 32)WD repeats, coiled-coil domains, interacts with Utp188, 9, 12, 13, 33
Utp22YGR090w141YesNOL6 (NRAP; 24)Ribosome biogenesis and homolog of human Nrap8, 9, 12, 33, 38
Emg1Nep1YLR186w27.3YesC2Fc (53)Required for 40S biogenesis and interacts with Nop14; one peptide in purification4, 9, 21
Krr1YCL059c37.2YesHRB2 (NP008974.3; 61)Required for 18S, KH domain, KRR-R motif8, 9, 13, 14, 32, 37
  • a DRIM, down-regulated in metastasis.

  • b HEAT, Huntington-elongation-A subunit-TOR; KH, lysine homology; KRR-R, lysine arginine arginine arginine.

  • c C2F is a possible homolog.