Maize Genetics Cooperation Newsletter

maize gene review

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


Review: pending

Pub date: May 2009

Name: crp1 -- chloroplast RNA processing1

Synonyms: CL1533_1, hcf111, hcf136

Chromosome: 7L bin 7.03
Genome Browser via cDNA AF073522 |gi| 3289001.

Function: translation of petA and psaC; stabilizes processed petB and petD mRNAs.

image of corn mutant

Summary: CRP1 is a member of the pentatricopeptide repeat family. CRP1 is required for the translation of the chloroplast petA and psaC mRNAs, and for the accumulation of processed petB and petD mRNAs. CRP1 associates in vivo with the 5' UTRs of the psaC and petA mRNAs. Null crp1 mutant alleles are pale green, non-photosynthetic and seedling lethal due to their lack of the cytochrome b6/f and photosystem I complexes.

Images: mutant leaf color depicited on a seedling color scale

First defining reports: Barkan et al. 1994; Cook and Miles 1988.

Key Alleles

crp1-m1::MuDR. MuDR insertion in exon. Pale yellow green, seedling lethal phenotype (Barkan et al. 1994).

crp1-hcf111::Mu1 (crp1-2): Mu1 insertion in exon. Pale yellow green, seedling lethal; high leaf chlorophyll fluorescence kinetics supports block in electron transport beyond the plastoquinone pool (Cook and Miles 1988).

5 other alleles have been found in the Photosynthesis Mutant Library (PML) collection (unpublished data).

Map Location

7L based on B-A chromosome translocation data.

Gene Product

CRP1 pentatricopeptide repeat protein.

Related Loci

Chloroplast genes psaC, petA. CRP1 protein associates with 5'-UTR of psaC and petA mRNA (Schmitz-Linneweber et al. 2005).


Barkan A, Walker M, Nolasco M, Johnson D (1994) A nuclear mutation in maize blocks the processing and translation of several chloroplast mRNAs and provides evidence for the differential translation of alternative mRNA forms. EMBO J 13: 3170-3181. PUBMED 8039510

Cook WB, Miles D (1988) Transposon mutagenesis of nuclear phtosynthetic genes in Zea mays. Photosynthesis Research 18:33-59. Article

Fisk DG, Walker MB, Barkan A (1999) Molecular cloning of the maize gene crp1 reveals similarity between regulators of mitochondrial and chloroplast gene expression. EMBO J. 18: 2621-2630. PUBMED

Schmitz-Linneweber C, Williams-Carrier R, Barkan A (2005) RNA immunoprecipitation and microarray analysis shows a chloroplast PPR protein to be associated with the 5'- region of mRNAs whose translation it activates. Plant Cell 17: 2791-2804. PUBMED

Links: MGDB: crp1 NCBI:crp1 UniProt: O81397