Reference "CRS1 is a novel group II intron splicing factor that was derived from a domain of ancient origin"

Reference ID

8486

Title

CRS1 is a novel group II intron splicing factor that was derived from a domain of ancient origin

Source

RNA, 2001, vol. 7, pp. 1227-1238

Authors (4)

Till-B	Schmitz-Linneweber-C
Williams-Carrier-R	Barkan-A

Abstract

Protein-dependent group II intron splicing provides a forum for exploring the
roles of proteins in facilitating RNA-catalyzed reactions. The maize nuclear
gene crs1 is required for the splicing of the group II intron in the chloroplast
atpF gene. Here we report the molecular cloning of the crs1 gene and an initial
biochemical characterization of its gene product. Several observations support
the notion that CRS1 is a bona fide group II intron splicing factor. First, CRS1
is found in a ribonucleoprotein complex in the chloroplast, and cofractionation
data provide evidence that this complex includes atpF intron RNA. Second, CRS1
is highly basic and includes a repeated domain with features suggestive of a
novel RNA-binding domain. This domain is related to a conserved free-standing
open reading frame of unknown function found in both the eubacteria and archaea.
crs1 is the founding member of a gene family in plants that was derived by
duplication and divergence of this primitive gene. In addition to its previously
established role in atpF intron splicing, new genetic data implicate crs1 in
chloroplast translation. The chloroplast splicing and translation functions of
crs1 may be mediated by the distinct protein products of two crs1 mRNA forms
that result from alternative splicing of the crs1 pre-mRNA.