Maize Genetics Cooperation Newsletter

maize gene review

Author: Alice Barkan, University of Oregon, Eugene, OR. USA 97403


Review: pending

Pub date: May 2009

Name: crs1--chloroplast RNA splicing1

Synonyms: CL1179_1; PZA01994

Chromosome 1L bin 1.07
Genome Browser via cDNA AF290414 |gi|9837549

Function: chloroplast atpF RNA splicing

image of corn mutant

Summary: CRS1 is required specifically for the splicing of the group II intron in the chloroplast atpF gene. CRS1 binds with specificity to this intron both in vivo and in vitro. CRS1 has three "CRM" domains, an RNA binding domain found in various mitochondrial and chloroplast splicing factors. Mutations in crs1 cause a pale green non-photosynthetic, seedling lethal phenotype due to the absence of the chloroplast ATP synthase complex.

Image: mutant leaf color depicted on a seedling leaf color scale

First Report: Jenkins et al. 1997.

Key Alleles

crs1-1::MuDr. MuDr insertion is upstream of the start ATG. (Till et al. 2001) Slightly pale green, seedling lethal phenotype. This allele is supressible.

crs1-2::Mu1. Mu1 insertion in the first exon. (Till et al. 2001) Very pale yellow green, seedling lethal phenotype.

4 other alleles arising independently from active Mu lines have been found in the photosynthesis mutant library (PML) collection (unpublished data).

Map Location

Mapped to chromosome 1L based on chromosome B-A translocation data (Jenkins 1997) and hybridization of overgo probe CL1179_1_ov to the B73 BAC FPC physical map (Gardiner et al. 2004; Wei et al. 2009).

Gene Product

CRS1, required specifically for splicing of the chloroplast group II intron in the chloroplast atpF gene (Asakura and Barkan 2006, Barkan et al. 2007, Jenkins et al. 1997, Ostersetzer et al. 2005, Till et al. 2001).


Asakura Y, Barkan A (2006) Arabidopsis orthologs of maize chloroplast splicing factors promote splicing of orthologous and species-specific group II introns. Plant Physiology 142:1656-1663. PUBMED

Barkan A, Klipcan L, Ostersetzer O, Kawamura T, Asakura Y, Watkins K (2007) The CRM domain: an RNA binding module derived from an ancient ribosome-associated protein. RNA, 13:55-64. PUBMED

Gardiner J, Schroeder S, Schaeffer (Polacco) ML, Sanchez-Villeda H, Fang Z, Morgante M, Landewe T, Fengler K, Useche F, Hanafey M, Tingey SV, Chou H, Wing R, Soderlund CA, Coe E (2004) Anchoring 9,371 maize expressed sequence tagged unigenes to the bacterial artificial chromosome contig map by two-dimensional overgo hybridization. Plant Physiology 134:1317-1326. PUBMED

Jenkins B, Kulhanek D, Barkan A (1997) Nuclear mutations that block group II RNA splicing in maize chloroplasts reveal several intron classes with distinct requirements for splicing factors. Plant Cell, 9:283-296. PUBMED

Ostersetzer O, Cooke AM, Watkins KP and Barkan A (2005) CRS1, a chloroplast group II intron splicing factor, promotes intron folding through specific interactions with two intron domains. Plant Cell, 17:241-255 PUBMED

Till B, Schmitz-Linneweber C, Williams-Carrier R, and Barkan A (2001) CRS1 is a novel group II intron splicing factor that was derived from a domain of ancient origin. RNA. 7:1227-1238. PUBMED

Wei F et al 2009 submitted. FPC map

Links: MGDB:crs1 NCBI:crs1 Uniprot:Q9FYT6