Abstract:Arabidospsis IQM2,the second member of the IQM family,is encoded by At3g13600. Its cDNA sequence,however,can not be found in any molecular biology literature or database.Using RACE and RT-PCR methods,a 2245 bp long full-length cDNA of Arabidopsis IQM2 was cloned in this study.Its open reading frame (ORF) was 1818 bp long and encoded for a 605-amino-acid polypeptide.Bioinformatics analysis revealed that the polypeptide had an IQ motif and shared sequence homology with the pea heavy metal induced protein 6A in its N-terminus and a ribosome inactivating protein,trichosanthin,in its C-terminus.The IQ motif located in the homologous region of the pea heavy metal -induced protein 6A.