Four genes in two diverged subfamilies encode the ribulose-1,5-bisphosphate carboxylase small subunit polypeptides of Arabidopsis thaliana

Abstract

The multigene family encoding the small subunit polypeptides of ribulose-1,5-bisphosphate carboxylase/oxygenase in the crucifer Arabidopsis thaliana has been isolated and the organization and structure of the individual members determined. The family consists of four genes which have been divided into two subfamilies on the basis of linkage and DNA and amino acid sequence similarities. Three of the genes, designated ats1B, ats2B, and ats3B, reside in tandem on an 8 kb stretch of the chromosome. These genes share greater than 95% similarity in DNA sequence and encode polypeptides identical in length and 96.7% similar in amino acid sequence. The fourth gene, ats1A, is at least 10 kb removed from, or completely unlinked to the B subfamily. The B subfamily genes are more similar to each other than to ats1A in nucleotide and amino acid sequence. All four genes are interupted by two introns whose placement within the coding region of the genes is conserved. The introns of the B subfamily genes are similar in length and nucleotide sequence, but show no similarity to the introns of ats1A. Comparison of the DNA sequences within the immediate 5' and 3' flanking sequences among the genes revealed only limited regions of homology. S1 analysis shows that all four genes are expressed.

Developmental and age-related processes that influence the longevity and senescence of photosynthetic tissues in arabidopsis.

“…The chlorophyll alb binding protein (CAS) probe, pAB 140, was obtained from E. Tobin (University of California, Los Angeles) (Leutwiler e1 al., 1986). The ribulose bisphosphate carboxylase small subunit (rbcS) probe, pATS-3, is a genomic clone that spans the promoter and the 5' half of the coding sequence of the ATS3B member of the rbcS gene family (Krebbers et al, 1988). The elongation factor (EF)-Ia probe was made by polymerase chain reaction amplification with oligonucleotides designed to be unique to EF-laA4 (Curie et al, 1991), and the amplified fragment was cloned into Bluescript KS+ (Stratagene).…”

A New Class of Arabidopsis Constitutive Photomorphogenic Genes Involved in Regulating Cotyledon Development.

“…Filter hybridizations were performed at 65OC in a solution containing 7% SDS, 500 mM NaH2P04, pH 7.2,1% BSA, and 1 mM EDTA. The DNA probes used are as follows: a 0.55-kb DNA fragment (generated by polymerase chain reaction) corresponding to the entire open reading frame of the Arabidopsis small subunit of ribulose-l,5-bisphosphate carboxylase rbcS gene (Krebbers et al, 1988); a 0.5-kb BamHI-Sstl DNA fragment corresponding to the coding region of the Arabidopsis chlorophyll alb (cab3) gene (Leutwiler et al, 1986); a 1.5-kb Hincll-ECORI DNA fragment containing the Arabidopsis ferredoxin type A (fedA) gene (Somers et al, 1990); a 1.2-kb Bglll-Xbal DNA fragment containing most of the coding region of a spinach chloroplast plastid @sbA) gene (Zurawski et al, 1982); and a 2-kb Hindlll fragment containing the entire p-glucuronidase (GUS) coding sequence used for the cabl promoter-GUS constructs (Deng et al, 1991). For all probes, -200 ng of each purified DNA fragment was labeled to high specific activity (-2 to 3 x 105 cpmlng DNA) by random oligomer priming, denatured by boiling for 5 min, and used for hybridization.…”

Unique and Overlapping Expression Patterns among Members of Photosynthesis-Associated Nuclear Gene Families in Arabidopsis

“…Rubisco is a multimeric enzyme consisting of eight small subunits and eight large subunits (Baker et al, 1975), and while the large subunits are encoded by a single chloroplast gene (Bedbrook et al, 1979), the small subunits are encoded by a family of nuclear genes (Dean et al, 1989). In Arabidopsis (Arabidopsis thaliana), the RbcS gene family comprises four members (RbcS1A, RbcS1B, RbcS2B, RbcS3B) that have been divided into two subfamilies, A and B, on the basis of linkage and sequence similarities (Krebbers et al, 1988).…”