Excised group II introns in yeast mitochondria are lariats and can be formed by self-splicing in vitro

Veen, Renske M. van der; Arnberg, Annika C.; Horst, G.; Bonen, Linda; Tabak, Henk F.; Grivell, Leslie A.

doi:10.1016/0092-8674(86)90756-7

Cited by 323 publications

(141 citation statements)

References 32 publications

Supporting

Mentioning

135

Contrasting

Unclassified

Order By: Relevance

“…In the first, the 2Ј-hydroxyl of a bulged adenosine near the end of the intron, in domain VI, triggers a nucleophilic attack on the 5Ј splice site. In the second reaction, the 2Ј-5Ј branched product is released as a lariat when the free 3Ј-OH at the end of the 5Ј exon attacks the 3Ј splice junction joining the two exons (2)(3)(4)(5). In ai5␥, a yeast mitochondrial group IIB intron, the functional group II intron branch site consists of the bulged adenosine, the wobble pairs (G-U) flanking this residue and, possibly, the purine-enriched sequence in domain VI on the strand opposite the bulged nucleotide (6 -8).…”

mentioning

confidence: 99%

Relevance of the Branch Point Adenosine, Coordination Loop, and 3′ Exon Binding Site for in Vivo Excision of the Sinorhizobium meliloti Group II Intron RmInt1

Molina-Sánchez¹,

Barrientos‐Durán²,

Toro

2011

Journal of Biological Chemistry

View full text Add to dashboard Cite

Excision of the bacterial group II intron RmInt1 has been demonstrated in vivo, resulting in the formation of both intron lariat and putative intron RNA circles. We show here that the bulged adenosine in domain VI of RmInt1 is required for splicing via the branching pathway, but branch site mutants produce small numbers of RNA molecules in which the first G residue of the intron is linked to the last C residue. Mutations in the coordination loop in domain I reduced splicing efficiency, but branched templates clearly predominated among splicing products. We also found that a single substitution at the EBS3 position (G329C), preventing EBS3-IBS3 pairing, resulted in the production of 50 to 100 times more RNA molecules in which the 5 and 3 extremities were joined. We provide evidence that these intron molecules may correspond to both, intron circles linked by a 2-5 phosphodiester bond, and tandem, head-to-tail intron copies.Group II introns are large catalytic RNAs with a conserved secondary structure consisting of six domains arranged around a central wheel (1). Group II introns may self-splice via several different pathways (Fig. 1). The main splicing pathway in group II introns involves two sequential trans-esterification reactions. In the first, the 2Ј-hydroxyl of a bulged adenosine near the end of the intron, in domain VI, triggers a nucleophilic attack on the 5Ј splice site. In the second reaction, the 2Ј-5Ј branched product is released as a lariat when the free 3Ј-OH at the end of the 5Ј exon attacks the 3Ј splice junction joining the two exons (2-5). In ai5␥, a yeast mitochondrial group IIB intron, the functional group II intron branch site consists of the bulged adenosine, the wobble pairs (G-U) flanking this residue and, possibly, the purine-enriched sequence in domain VI on the strand opposite the bulged nucleotide (6 -8). Recent studies have reported the presence, within domain I of group IIB introns, of a branch site receptor known as a coordination loop (9), which is required for trans-esterification (8), but these findings have been called into question (10). This coordination loop has been identified as a key element for exon ligation, as it positions the exon and intron binding sequences, the EBS3-IBS3 base pair and the EBS1-IBS1 helix, in an appropriate conformation for reaction (9). There is also an alternative splicing pathway, the first step of which involves hydrolysis. The ligated exons and linear intron are then generated in a standard second step (11-13). An additional excision reaction, in which the intron is excised as a putative circle, has also been proposed for some group II introns (14 -16). In this case, prior release of the 3Ј exon from the precursor molecules, presumably via a transsplicing mechanism, seems to be required for the generation of a putative 2Ј-5Ј ligated circular intron. The origin and function of such intron circles in vivo remains unknown.RmInt1 is a mobile subclass IIB3 intron (17). It has also been assigned to phylogenetic bacterial class D (17, 18) on the basis o...

show abstract

mentioning

confidence: 99%

Relevance of the Branch Point Adenosine, Coordination Loop, and 3′ Exon Binding Site for in Vivo Excision of the Sinorhizobium meliloti Group II Intron RmInt1

Molina-Sánchez¹,

Barrientos‐Durán²,

Toro

2011

Journal of Biological Chemistry

View full text Add to dashboard Cite

show abstract

“…However, the relative cross-peak intensities in fingerprint regions, such as the H1Ј-H6/8 and H2Ј/H2Љ-H6/8 cross-peaks in the 3ϩ (data not shown). 3 This means that neither metal ion causes significant changes in the d3ЈEBS1⅐dIBS1 structure.…”

Section: C(mgmentioning

confidence: 99%

“…Group II introns are large ribozymes and mobile genetic elements capable of catalyzing their own splicing reaction (1)(2)(3). During splicing, the intron RNA excises itself from an RNA transcript in two sequential phosphotransesterification reactions that yield the two ligated exons and the excised intron in a lariat structure.…”

mentioning

confidence: 99%

The Role of Mg(II) in DNA Cleavage Site Recognition in Group II Intron Ribozymes

Skilandat

Sigel

2014

Journal of Biological Chemistry

View full text Add to dashboard Cite

Background: Group II introns cleave DNA and RNA 3Ј of a short duplex formed between the intron and the target. Results: We present the NMR structure of this hybrid duplex and describe two distinct Mg 2ϩ binding sites. Conclusion:The hybrid is asymmetric and strongly stabilized by Mg 2ϩ binding. Significance: Site-bound metal ions are crucially important for group II intron cleavage site recognition.

show abstract

“…5,6 The unveiling of catalytic RNA has transformed the scientific community's perception of RNA and has led to the birth of an entire new field devoted to the study of the structure and function of RNA. Numerous examples of catalytic RNAs have since been found to function in processes such as viral replication (HDV, hammerhead, hairpin, and other small ribozymes [7][8][9] ), protein translation, 10 and the maturation of tRNAs (RNase P 6 ), rRNAs (RNase MRP 11 ), and mRNAs (self-splicing introns 5,12,13 and possibly the spliceosome, 14,15 itself a Nobel-winning discovery by Phil Sharp and Richard Roberts). As a result we now have a fairly sophisticated understanding of RNA's capabilities and limitations.…”

mentioning

confidence: 99%

RNA takes center stage

Todd

Karbstein

2007

Biopolymers

View full text Add to dashboard Cite

Excised group II introns in yeast mitochondria are lariats and can be formed by self-splicing in vitro

Cited by 323 publications

References 32 publications

Relevance of the Branch Point Adenosine, Coordination Loop, and 3′ Exon Binding Site for in Vivo Excision of the Sinorhizobium meliloti Group II Intron RmInt1

Relevance of the Branch Point Adenosine, Coordination Loop, and 3′ Exon Binding Site for in Vivo Excision of the Sinorhizobium meliloti Group II Intron RmInt1

The Role of Mg(II) in DNA Cleavage Site Recognition in Group II Intron Ribozymes

RNA takes center stage

Contact Info

Product

Resources

About