Ribonucleoprotein complex containing small nuclear RNA U1; a component of the major spliceosome complex.

Ribonucleoprotein complex containing small nuclear RNA U2; a component of the major spliceosome complex.

Ribonucleoprotein complex containing small nuclear RNA U4; a component of the major spliceosome complex.

Ribonucleoprotein complex containing small nuclear RNA U6; a component of the major spliceosome complex.

The minor (U12-dependent) spliceosome is composed of the snRNPs, U11, U12, U4atac, U6atac, and U5 (which is also a component of the major spliceosome). This minor form of the spliceosome is responsible for the splicing of the majority of introns with atypical AT-AC terminal dinucleotides, as well as other non-canonical introns. The entire splice site signal, not just the terminal dinucleotides, is involved in determining which spliceosome utilizes the site.

A multiprotein complex that possesses histone acetyltransferase and is involved in regulation of transcription. The budding yeast complex includes Gcn5p, two proteins of the Ada family, and two TBP-associate proteins (TAFs); analogous complexes in other species have analogous compositions, and usually contain homologs of the yeast proteins.

A component of the transcription machinery of RNA Polymerase II. In humans, TFIIA is a heterotrimer composed of an alpha (P35), beta (P19) and gamma subunits (P12).

Catalysis of the reaction: ATP + N-acyl-D-mannosamine = ADP + N-acyl-D-mannosamine 6-phosphate.

A transcription factor which in humans consists of a complex of two alpha and two beta chains. Recruits TFIIH to the initiation complex and helps activate both RNA polymerase II and TFIIH.

A general transcription initiation factor which in humans consists of a heterodimer of an alpha and a beta subunit. Helps recruit RNA polymerase II to the initiation complex and promotes translation elongation.

Translational attentuation is a regulatory mechanism analogous to ribosome-mediated transcriptional attenuation. The system requires the presence of a short ORF, called a leader peptide, encoded in the mRNA upstream of the ribosome-binding site and start codon of the gene whose translation is to be regulated. Certain conditions, such as presence of the antibiotic tetracycline in bacteria or amino acid starvation, may cause slowing or stalling of the ribosome translating the leader peptide. The stalled ribosome masks a region of the mRNA and affects which of two alternative mRNA folded structures will form, therefore controlling whether or not a ribosome will bind and initiate translation of the downstream gene. Translational attenuation is analogous to ribosome-mediated transcriptional attenuation, in which mRNA remodeling caused by ribosome stalling regulates transcriptional termination rather than translational initiation.