Formation of the Spliceosomal E complex

Stable Identifier
R-HSA-72107
Type
Reaction
Species
Homo sapiens
Compartment
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Summation

Pre-mRNA transcripts become rapidly associated with many RNA-binding proteins, including hnRNP proteins, cap-binding proteins, SR proteins, etc; in the test tube this binding does not require splice sites or ATP. The E complex, or early complex, is the first detectable functional intermediate in spliceosome assembly in vitro. It is an ATP-independent complex. When a functional 5' splice site is present, it is bound by the U1 snRNP. The splicing factor U2AF (65 and 35 kDa subunits) binds to the polypyrimidine tract (Y)n and the AG dinucleotide at the 3' splice site, respectively. SF1/mBBP binds to the branch site. Binding of many of these factors is cooperative; e.g., SR proteins and U2AF apparently interact with each other, facilitating their binding to the pre-mRNA. In the presence of ATP, the E complex is converted to the first ATP-dependent spliceosomal complex, namely the A complex.

Literature References
PubMed ID Title Journal Year
12477934 Protein composition of human prespliceosomes isolated by a tobramycin affinity-selection method.

Hartmuth, K, Urlaub, H, Vornlocher, HP, Will, CL, Gentzel, M, Wilm, M, Lührmann, R

Proc Natl Acad Sci U S A 2002
26420826 Mammalian splicing factor SF1 interacts with SURP domains of U2 snRNP-associated proteins

Crisci, A, Raleff, F, Bagdiul, I, Raabe, M, Urlaub, H, Rain, JC, Krämer, A

Nucleic Acids Res. 2015
12176931 Large-scale proteomic analysis of the human spliceosome.

Rappsilber, J, Ryder, U, Lamond, AI, Mann, M

Genome Res 2002
22110043 Functional mammalian spliceosomal complex E contains SMN complex proteins in addition to U1 and U2 snRNPs

Makarov, EM, Owen, N, Bottrill, A, Makarova, OV

Nucleic Acids Res. 2012
22365833 Dynamic protein-protein interaction wiring of the human spliceosome

Hegele, A, Kamburov, A, Grossmann, A, Sourlis, C, Wowro, S, Weimann, M, Will, CL, Pena, V, Lührmann, R, Stelzl, U

Mol. Cell 2012
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