Biomaterial Database

Identification and expression of the chloroplast clpP gene in the conifer Pinus contorta. 1994

A K Clarke, and P Gustafsson, and J A Lidholm

Department of Plant Physiology, University of Umeå, Sweden.

The clpP gene from the conifer Pinus contorta was identified and isolated from a chloroplast genomic library by heterologous hybridisation to the second exon of the chloroplast clpP gene in tobacco. DNA sequencing of two overlapping clones revealed an uninterrupted 615 bp open-reading frame with 41 to 65% similarity to the clpP genes in five other chloroplast genomes and Escherichia coli. The 615 bp sequence in P. contorta contained perfectly matched motifs for the serine and histidine active sites of the ClpP protease in E. coli. The location of the clpP gene was determined using a physical map of the P. contorta chloroplast genome, and was found to lie within a 10 kb region between the psbE/F and rpoB genes. Sequencing of the regions adjacent to the clpP gene revealed the first exon of the rps12 gene located 135 bp downstream. The genomic position of the first exon of the rps12 gene in relation to the clpP gene is conserved for all other chloroplast clpP genes identified so far. Northern blot analysis showed that the clpP gene in both P. contorta and P. sylvestris was present in several transcript of different length, ranging from 0.8 to 2.4 kb. The two longer transcripts in P. contorta also included the first exon of the rps12 gene. Mapping of the 5' end of the clpP transcripts by primer extension, however, revealed a single transcription initiation site 53 bp upstream of the first ATG codon. Analysis of total RNA isolated from the two pine species grown in darkness or moderate light conditions (250 mumol photons m-2 s-1) showed no significance difference in the level of expression of the clpP gene. The results suggest that the clpP gene in conifers is part of an operon which includes the first exon of the rps12 and the entire rpl20 gene, and is expressed in a light-independent manner as a polycistronic precursor which later undergoes post-transcriptional processing to give the mature monocistronic clpP mRNA.

UI	MeSH Term	Description	Entries
D008969	Molecular Sequence Data	Descriptions of specific amino acid, carbohydrate, or nucleotide sequences which have appeared in the published literature and/or are deposited in and maintained by databanks such as GENBANK, European Molecular Biology Laboratory (EMBL), National Biomedical Research Foundation (NBRF), or other sequence repositories.	Sequence Data, Molecular,Molecular Sequencing Data,Data, Molecular Sequence,Data, Molecular Sequencing,Sequencing Data, Molecular
D009876	Operon	In bacteria, a group of metabolically related genes, with a common promoter, whose transcription into a single polycistronic MESSENGER RNA is under the control of an OPERATOR REGION.	Operons
D010940	Plant Proteins	Proteins found in plants (flowers, herbs, shrubs, trees, etc.). The concept does not include proteins found in vegetables for which PLANT PROTEINS, DIETARY is available.	Plant Protein,Protein, Plant,Proteins, Plant
D002736	Chloroplasts	Plant cell inclusion bodies that contain the photosynthetic pigment CHLOROPHYLL, which is associated with the membrane of THYLAKOIDS. Chloroplasts occur in cells of leaves and young stems of plants. They are also found in some forms of PHYTOPLANKTON such as HAPTOPHYTA; DINOFLAGELLATES; DIATOMS; and CRYPTOPHYTA.	Chloroplast,Etioplasts,Etioplast
D003001	Cloning, Molecular	The insertion of recombinant DNA molecules from prokaryotic and/or eukaryotic sources into a replicating vehicle, such as a plasmid or virus vector, and the introduction of the resultant hybrid molecules into recipient cells without altering the viability of those cells.	Molecular Cloning
D006360	Heat-Shock Proteins	Proteins which are synthesized in eukaryotic organisms and bacteria in response to hyperthermia and other environmental stresses. They increase thermal tolerance and perform functions essential to cell survival under these conditions.	Stress Protein,Stress Proteins,Heat-Shock Protein,Heat Shock Protein,Heat Shock Proteins,Protein, Stress
D000595	Amino Acid Sequence	The order of amino acids as they occur in a polypeptide chain. This is referred to as the primary structure of proteins. It is of fundamental importance in determining PROTEIN CONFORMATION.	Protein Structure, Primary,Amino Acid Sequences,Sequence, Amino Acid,Sequences, Amino Acid,Primary Protein Structure,Primary Protein Structures,Protein Structures, Primary,Structure, Primary Protein,Structures, Primary Protein
D001483	Base Sequence	The sequence of PURINES and PYRIMIDINES in nucleic acids and polynucleotides. It is also called nucleotide sequence.	DNA Sequence,Nucleotide Sequence,RNA Sequence,DNA Sequences,Base Sequences,Nucleotide Sequences,RNA Sequences,Sequence, Base,Sequence, DNA,Sequence, Nucleotide,Sequence, RNA,Sequences, Base,Sequences, DNA,Sequences, Nucleotide,Sequences, RNA
D012697	Serine Endopeptidases	Any member of the group of ENDOPEPTIDASES containing at the active site a serine residue involved in catalysis.	Serine Endopeptidase,Endopeptidase, Serine,Endopeptidases, Serine
D013045	Species Specificity	The restriction of a characteristic behavior, anatomical structure or physical system, such as immune response; metabolic response, or gene or gene variant to the members of one species. It refers to that property which differentiates one species from another but it is also used for phylogenetic levels higher or lower than the species.	Species Specificities,Specificities, Species,Specificity, Species