Extreme divergence of a novel wheat thionin generated by a mutational burst specifically affecting the mature protein domain of the precursor.
A new type of neutral thionin (type V), specifically expressed in developing wheat endosperm, has been found to be encoded by a set of single-copy genes located in the long arms of chromosomes 1A, 1B and 1D, within less than 10,000 base-pairs of those corresponding to the highly basic type-I thionins. Divergence between types I and V has occurred through a process of accelerated evolution that has affected the amino acid sequence of the mature thionin but not the precursor domains corresponding to the N-terminal signal peptide and the long C-terminal acidic peptide. This process involved a deletion and a non-synonymous nucleotide substitution rate equal to the synonymous rate in the thionin sequence.
Castagnaro
A
A
Area de Bioquímica y Biología Molecular. E.T.S Ingenieros Agrónomos, UPM., Madrid, Spain.
Maraña
C
C
Carbonero
P
P
García-Olmedo
F
F
D000595:Amino Acid Sequence; D023181:Antimicrobial Cationic Peptides; D001483:Base Sequence; D005075:Biological Evolution; D002874:Chromosome Mapping; D003001:Cloning, Molecular; D004247:DNA / Q000235:genetics; D015870:Gene Expression; D017343:Genes, Plant; D007438:Introns; D008969:Molecular Sequence Data; D009838:Oligodeoxyribonucleotides / Q000737:chemistry; D010940:Plant Proteins / Q000235:genetics*; D016133:Polymerase Chain Reaction; D012333:RNA, Messenger / Q000235:genetics; D014908:Triticum / Q000235:genetics*
D023181:Antimicrobial Cationic Peptides; D009838:Oligodeoxyribonucleotides; D010940:Plant Proteins; D012333:RNA, Messenger; C074252:TthV protein, wheat; D004247:DNA