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RNase X2, a pistil-specific ribonuclease from Petunia inflata, shares sequence similarity with solanaceous S proteins.
- Source :
-
Plant molecular biology [Plant Mol Biol] 1992 Dec; Vol. 20 (6), pp. 1131-41. - Publication Year :
- 1992
-
Abstract
- Petunia inflata, a species with gametophytic self-incompatibility, has previously been found to contain a large number of ribonucleases in the pistil. The best characterized of the pistil ribonucleases are the products of the S alleles, the S proteins, which are thought to be involved in self-incompatibility interactions. Here we report the characterization of a gene encoding another pistil ribonuclease of P. inflata, RNase X2. Degenerate oligonucleotides, synthesized based on the amino-terminal sequence of RNase X2, were used as probes to isolate cDNA clones, one of which was in turn used as a probe to isolate genomic clones containing the gene for RNase X2, rnx2. The deduced amino acid sequence of RNase X2 shows 42% to 71% identity to the 20 solanaceous S proteins reported so far, with the highest degree of similarity being to S3 and S6 proteins of Nicotiana alata. The cDNA sequence predicts a leader peptide of 22 amino acids, suggesting that RNase X2, like S proteins, is an extracellular ribonuclease. Also, similar to the S gene, rnx2 is expressed only in the pistil, and contains a single intron comparable in size and identical in location to that of the S gene. However, rnx2 is not linked to the S locus, and, in contrast to the highly polymorphic S gene, it is monomorphic. The possible biological function of RNase X2 is discussed.
Details
- Language :
- English
- ISSN :
- 0167-4412
- Volume :
- 20
- Issue :
- 6
- Database :
- MEDLINE
- Journal :
- Plant molecular biology
- Publication Type :
- Academic Journal
- Accession number :
- 1463846
- Full Text :
- https://doi.org/10.1007/BF00028899