Abstract:

To clarify the expression characteristics of eukaryotic initiation factors [eIF(iso)4E] and
the interaction relationship of eIF(iso)4E with TuMV VPg，the eIF(iso)4E.a and eIF(iso)4E.c genes were
cloned from the Brassica rapa ssp. chinensis materials‘Jizaochun’and‘BP8407’，respectively. Both of
the two genes could encode 200 amino acids. The yeast two-hybridand bimolecular fluorescence
complementation（BiFC）results showed that TuMV-C4 could only interact with eIF(iso)4E.a，instead of
eIF(iso)4E.c；the TuMV-UK1 could only interact with eIF(iso)4E.c，instead of eIF(iso)4E.a. Analyzing the amino acid sequence and the domain tertiary structure of eIF(iso)4E protein revealed that it contained the
cap-reception site. There were 20 different amino acids between eIF(iso)4E.a and eIF(iso)4E.c，17 of
which were located in the cap-reception site（accounting for 85%）. Through aligning the TuMV-C4/UK1
VPg amino acid sequences，four different amino acids were found；and after comparative analyzing the
sequences from different TuMV strains，the frequency of the amino acids had certain selectivity in the four
amino acid points.

Key words: Brassica rapa ssp. chinensis, eIF(iso)4E, TuMV, VPg（virus genome-linked protein）, protein interaction