Biomaterial Database

Expression and processing of an unusual tRNA gene cluster in the cyanobacterium Anabaena sp. PCC 7120. 2012

Leonor Puerto-Galán, and Agustín Vioque

Instituto de Bioquímica Vegetal y Fotosíntesis, Universidad de Sevilla and CSIC, Sevilla, Spain.

Anabaena sp. PCC 7120 is a filamentous cyanobacterium that bears a cluster of 26 tRNA genes and pseudogenes in the delta plasmid. The sequences of these tRNAs suggest that they have been acquired by horizontal gene transfer from another organism. The cluster is transcribed as a single transcript that is quickly processed to individual tRNAs. RNase P and RNase Z, in vitro, are able to process precursors containing some of these tRNAs. Deletion of the cluster causes no obvious phenotype or effect on growth under diverse culture conditions, indicating that the tRNAs encoded in the cluster are not required for growth under laboratory conditions, although they are aminoacylated in vivo. We have studied a possible tRNA(Ser) [tRNA(Ser) GCU(2)] present in the cluster with a sequence that deviates from consensus. This tRNA is processed in vitro by RNase P at the expected position. In addition, this tRNA(Ser) GCU is specifically aminoacylated with serine by an Anabaena sp. PCC 7120 crude extract. These data indicate that tRNA(Ser) GCU(2) is fully functional, despite its unusual structure. Similar clusters are found in other three cyanobacteria whose genomes have been sequenced.

UI	MeSH Term	Description	Entries
D010957	Plasmids	Extrachromosomal, usually CIRCULAR DNA molecules that are self-replicating and transferable from one organism to another. They are found in a variety of bacterial, archaeal, fungal, algal, and plant species. They are used in GENETIC ENGINEERING as CLONING VECTORS.	Episomes,Episome,Plasmid
D005810	Multigene Family	A set of genes descended by duplication and variation from some ancestral gene. Such genes may be clustered together on the same chromosome or dispersed on different chromosomes. Examples of multigene families include those that encode the hemoglobins, immunoglobulins, histocompatibility antigens, actins, tubulins, keratins, collagens, heat shock proteins, salivary glue proteins, chorion proteins, cuticle proteins, yolk proteins, and phaseolins, as well as histones, ribosomal RNA, and transfer RNA genes. The latter three are examples of reiterated genes, where hundreds of identical genes are present in a tandem array. (King & Stanfield, A Dictionary of Genetics, 4th ed)	Gene Clusters,Genes, Reiterated,Cluster, Gene,Clusters, Gene,Families, Multigene,Family, Multigene,Gene Cluster,Gene, Reiterated,Multigene Families,Reiterated Gene,Reiterated Genes
D000604	Amino Acyl-tRNA Synthetases	A subclass of enzymes that aminoacylate AMINO ACID-SPECIFIC TRANSFER RNA with their corresponding AMINO ACIDS.	Amino Acyl T RNA Synthetases,Amino Acyl-tRNA Ligases,Aminoacyl Transfer RNA Synthetase,Aminoacyl-tRNA Synthetase,Transfer RNA Synthetase,tRNA Synthetase,Acyl-tRNA Ligases, Amino,Acyl-tRNA Synthetases, Amino,Amino Acyl tRNA Ligases,Amino Acyl tRNA Synthetases,Aminoacyl tRNA Synthetase,Ligases, Amino Acyl-tRNA,RNA Synthetase, Transfer,Synthetase, Aminoacyl-tRNA,Synthetase, Transfer RNA,Synthetase, tRNA,Synthetases, Amino Acyl-tRNA
D012323	RNA Processing, Post-Transcriptional	Post-transcriptional biological modification of messenger, transfer, or ribosomal RNAs or their precursors. It includes cleavage, methylation, thiolation, isopentenylation, pseudouridine formation, conformational changes, and association with ribosomal protein.	Post-Transcriptional RNA Modification,RNA Processing,Post-Transcriptional RNA Processing,Posttranscriptional RNA Processing,RNA Processing, Post Transcriptional,RNA Processing, Posttranscriptional,Modification, Post-Transcriptional RNA,Modifications, Post-Transcriptional RNA,Post Transcriptional RNA Modification,Post Transcriptional RNA Processing,Post-Transcriptional RNA Modifications,Processing, Posttranscriptional RNA,Processing, RNA,RNA Modification, Post-Transcriptional,RNA Modifications, Post-Transcriptional
D012343	RNA, Transfer	The small RNA molecules, 73-80 nucleotides long, that function during translation (TRANSLATION, GENETIC) to align AMINO ACIDS at the RIBOSOMES in a sequence determined by the mRNA (RNA, MESSENGER). There are about 30 different transfer RNAs. Each recognizes a specific CODON set on the mRNA through its own ANTICODON and as aminoacyl tRNAs (RNA, TRANSFER, AMINO ACYL), each carries a specific amino acid to the ribosome to add to the elongating peptide chains.	Suppressor Transfer RNA,Transfer RNA,tRNA,RNA, Transfer, Suppressor,Transfer RNA, Suppressor,RNA, Suppressor Transfer
D015870	Gene Expression	The phenotypic manifestation of a gene or genes by the processes of GENETIC TRANSCRIPTION and GENETIC TRANSLATION.	Expression, Gene,Expressions, Gene,Gene Expressions
D017033	Anabaena	A genus of CYANOBACTERIA consisting of trichomes that are untapered with conspicuous constrictions at cross-walls. A firm individual sheath is absent, but a soft covering is often present. Many species are known worldwide as major components of freshwater PLANKTON and also of many saline lakes. The species DOLICHOSPERMUM FLOS-AQUAE is responsible for acute poisonings of various animals.
D017384	Sequence Deletion	Deletion of sequences of nucleic acids from the genetic material of an individual.	Deletion Mutation,Deletion Mutations,Deletion, Sequence,Deletions, Sequence,Mutation, Deletion,Mutations, Deletion,Sequence Deletions
D043262	Ribonuclease P	An RNA-containing enzyme that plays an essential role in tRNA processing by catalyzing the endonucleolytic cleavage of TRANSFER RNA precursors. It removes the extra 5'-nucleotides from tRNA precursors to generate mature tRNA molecules.	Ribonuclease P, RNA Catalytic Subunit,RNA Catalytic Subunit, Ribonuclease P,RNase P