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-Structure paper
Title | Composition and three-dimensional EM structure of double affinity-purified, human prespliceosomal A complexes. |
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Journal, issue, pages | EMBO J, Vol. 26, Issue 6, Page 1737-1748, Year 2007 |
Publish date | Mar 21, 2007 |
Authors | Nastaran Behzadnia / Monika M Golas / Klaus Hartmuth / Bjoern Sander / Berthold Kastner / Jochen Deckert / Prakash Dube / Cindy L Will / Henning Urlaub / Holger Stark / Reinhard Lührmann / |
PubMed Abstract | Little is known about the higher-order structure of prespliceosomal A complexes, in which pairing of the pre-mRNA's splice sites occurs. Here, human A complexes were isolated under physiological ...Little is known about the higher-order structure of prespliceosomal A complexes, in which pairing of the pre-mRNA's splice sites occurs. Here, human A complexes were isolated under physiological conditions by double-affinity selection. Purified complexes contained stoichiometric amounts of U1, U2 and pre-mRNA, and crosslinking studies indicated that these form concomitant base pairing interactions with one another. A complexes contained nearly all U1 and U2 proteins plus approximately 50 non-snRNP proteins. Unexpectedly, proteins of the hPrp19/CDC5 complex were also detected, even when A complexes were formed in the absence of U4/U6 snRNPs, demonstrating that they associate independent of the tri-snRNP. Double-affinity purification yielded structurally homogeneous A complexes as evidenced by electron microscopy, and allowed for the first time the generation of a three-dimensional structure. A complexes possess an asymmetric shape (approximately 260 x 200 x 195 angstroms) and contain a main body with various protruding elements, including a head-like domain and foot-like protrusions. Complexes isolated here are well suited for in vitro assembly studies to determine factor requirements for the A to B complex transition. |
External links | EMBO J / PubMed:17332742 / PubMed Central |
Methods | EM (single particle) |
Resolution | 45.0 Å |
Structure data | EMDB-1325: |
Source |
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