Reference "Organization and expression of two tandemly oriented genes encoding ribulosebisphosphate carboxylase/oxygenase activase in barley"

Reference ID

8741

Title

Organization and expression of two tandemly oriented genes encoding ribulosebisphosphate carboxylase/oxygenase activase in barley

Source

The Journal of biological chemistry, 1991, vol. 266, pp. 4677-4685

Authors (2)

Rundle-S-J

Zielinski-R-E

Abstract

We have isolated and structurally characterized genomic DNA and cDNA sequences
encoding ribulose-1,5-bisphosphate carboxylase/oxygenase (Rbu-P2 carboxylase)
activase from barley (Hordeum vulgare L.). Three Rbu-P2 carboxylase activase
(Rca) polypeptides are encoded in the barley genome by two closely linked,
tandemly oriented nuclear genes (RcaA and RcaB); cDNAs encoding each of the
three Rbu-P2 carboxylase activase polypeptides were isolated from cDNA libraries
of barley leaf mRNA. RcaA produces two mRNAs, which encode polypeptides of 42
and 46 kDa, by an alternative splicing mechanism identical to that previously
reported for spinach and Arabidopsis Rca genes (Werneke, J.M., Chatfield, J.M.,
and Ogren, W. L. (1989) Plant Cell 1, 815-825). RcaB is transcribed to produce a
single mRNA, which encodes a mature peptide of 42 kDa. Genomic Southern blots
indicate that RcaA and RcaB represent the entire Rbu-P2 carboxylase activase
gene family in barley. The genes share 80% nucleotide sequence identity, and the
42-kDa polypeptides encoded by RcaA and RcaB share 87% amino acid sequence
identity. Coding regions of the two barley Rca genes are separated by 1 kilobase
pair of flanking DNA. DNA sequence motifs similar to those thought to control
light-regulated gene expression in other nuclear-encoded plastid polypeptide
genes are found at the 5' end of both barley Rca genes. Probes specific to three
mRNAs were used to determine the relative contribution each species makes to the
total Rca mRNA pool.