Biomaterial Database

Characterization of a Euglena gene encoding a polyprotein precursor to the light-harvesting chlorophyll a/b-binding protein of photosystem II. 1992

U S Muchhal, and S D Schwartzbach

School of Biological Sciences, University of Nebraska, Lincoln 68588.

A 7.4 kb segment of a Euglena nuclear gene encoding a portion of the polyprotein precursor to the light-harvesting chlorophyll a/b-binding protein of photosystem II (LHCPII) has been isolated and sequenced. Nine exons can be assembled into a continuous open reading frame encoding 113 amino acids of the C-terminus of an LHCPII, followed by 4 complete LHCPIIs. The intron-exon junctions required to maintain maximum amino acid sequence homology between the LHCPIIs encoded by the Euglena genomic clone and Arabidopsis LHCPII do not conform to the consensus splice site sequences present in most eukaryotic organisms. Three types of LHCPIIs are contained within the polyprotein precursor. There is greater than 90% sequence identity at both the protein and nucleic acid level within a type while between types, there is less than 65% sequence identity. All Euglena LHCPIIs contain three hydrophobic membrane-spanning domains in the same positions as found in other LHCPIIs. Hybridization of genomic Southern blots with a probe encoding LHCPII suggests that the Euglena genome encodes a large number (30-50) of LHCPIIs. A probe derived from the 3' end of the sequenced genomic clone hybridizes with equal intensity to 2-3 genomic fragments on Southern blots. The probe encoding LHCPII hybridizes to RNAs of 9.5 and 6.6 kb on northern blots of total RNA while the 3'-end probe hybridizes only to the 6.6 kb RNA. The 6.6 kb LHCPII band detected on northern blots appears to be composed of transcription products derived from 2-3 LHCPII genes. Euglena appears to be unique in that a large number of LHCPIIs are encoded by a small number (3-5) of polyprotein genes.

UI	MeSH Term	Description	Entries
D007438	Introns	Sequences of DNA in the genes that are located between the EXONS. They are transcribed along with the exons but are removed from the primary gene transcript by RNA SPLICING to leave mature RNA. Some introns code for separate genes.	Intervening Sequences,Sequences, Intervening,Intervening Sequence,Intron,Sequence, Intervening
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
D011498	Protein Precursors		Precursors, Protein
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
D005055	Euglena	A genus of EUKARYOTES, in the phylum EUGLENIDA, found mostly in stagnant water. Characteristics include a pellicle usually marked by spiral or longitudinal striations.	Euglenas
D005091	Exons	The parts of a transcript of a split GENE remaining after the INTRONS are removed. They are spliced together to become a MESSENGER RNA or other functional RNA.	Mini-Exon,Exon,Mini Exon,Mini-Exons
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
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
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
D015139	Blotting, Southern	A method (first developed by E.M. Southern) for detection of DNA that has been electrophoretically separated and immobilized by blotting on nitrocellulose or other type of paper or nylon membrane followed by hybridization with labeled NUCLEIC ACID PROBES.	Southern Blotting,Blot, Southern,Southern Blot