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Genomic RNA sequence of a tobamovirus infecting cruciferae plants (cr-TMV) was determined. The RNA is composed of 6312 nucleotides and contains four ORFs encoding the proteins of 122K (ORF1), 178K (ORF2), 29K (ORF3) and 18K (capsid protein, ORF4). ORF4 overlaps ORF3 by 74 nucleotides and the overlapping region can be folded into a stable hairpin structure. The 3'-terminal region of the cr-TMV RNA preceding the tRNA-like structure was shown to form six potentially stable pseudoknots.

The barley chloroplast psbA gene encoding D1 protein, one of the main photosystem II components, has been over-expressed in E. coli cells. The existance of two in vivo expression products, a protein with M(r) about 33.5 kDa, corresponding to the full-length precursor of the 32 kDa D1 mature form, and a truncated 29 kDa polypeptide was revealed. A modified D1 protein containing six histidine residues at the carboxy-terminus was also obtained. After isolation and renaturation, the ability of the recombinant D1 protein to bind atrazine and pigments from barley thylakoids was demonstrated.

A new modification of the oligonucleotide-mediated mutagenesis technique has been developed. The proposed methodology has been used to produce specific base changes in the double-stranded plasmid DNA. For this purpose, special cloning vectors have been constructed using the synthetic oligodeoxyribonucleotides. The developed method allows the production of mutant DNA from those of the wild-type with a yield of 10-20%.