Two new ribonucleoproteins (RNPs) have been identified from a @entity286 chloroplast lysate. These two proteins (cp29A and cp29B) are nuclear-encoded and have a less affinity to single-stranded DNA as compared with three other chloroplast RNPs (cp28, cp31 and cp33) previously isolated. DNA sequencing revealed that both contain two consensus sequence-type homologous RNA-binding domains (CS-RBDs) and a very acidic @entity1472 -terminal domain but shorter than that of cp28, cp31 and cp33. Comparison of cp29A and cp29B showed a 19 @entity535 insertion in the region separating the two CS-RBDs in cp29B. This insertion results in three tandem repeats of a @entity2228 -rich sequence of 10 @entity1522 , which is a novel feature in RNPs. The two proteins are encoded by different single nuclear genes and no alternatively spliced transcripts could be identified. We constructed a phylogenetic tree for the ten chloroplast CS-RBDs. These results suggest that there is a sizable RNP family in chloroplasts and the diversity was mainly generated through a series of gene duplications rather than through alternative pre-mRNA splicing. The gene for cp29B contains three introns. The first and second introns interrupt the first CS-RBD and the third intron does the second CS-RBD. The position of the first intron site is the same as that in the @entity1 @entity24092 protein gene.

Diversity of a ribonucleoprotein family in XXXX chloroplasts: two new chloroplast ribonucleoproteins and a phylogenetic tree of ten chloroplast RNA-binding domains.

@entity1 :: ('9606', 'Species') :: ['human'] @entity286 :: ('4097', 'Species') :: ['tobacco'] @entity1522 :: ('CHEBI:33709', 'Chemical') :: ['amino acids'] @entity1472 :: ('CHEBI:46882', 'Chemical') :: ['amino'] @entity2228 :: ('CHEBI:57305', 'Chemical') :: ['glycine'] @entity535 :: ('CHEBI:33704', 'Chemical') :: ['amino acid'] @entity24092 :: ('3178', 'Gene') :: ['hnRNP A1']
@entity286 :: (4097,Species) :: ['tobacco']
