THE 5'-UNTRANSLATED REGION OF ARABIDOPSIS-THALIANA CALMODULIN CDNA ISAN INDEPENDENT CDNA CONTAINING AN OPEN READING FRAME

A cDNA clone, pAUK1, with an open reading frame (ORF) coding for a hyp othetical 164-amino-acid protein was isolated from an Arabidopsis thal iana (L.) Heynh cDNA library. The clone was attached, tail to tail, to the 3' end of A. thaliana hexokinase cDNA, An almost identical sequen ce had been previously described as the 5' untranslated region (5' UTR ) of A. thaliana calmodulin cDNA (ACaM-2). Sequence comparison with th ree additional A. thaliana truncated cDNA clones which appear in a dat abase (GenBank) supports the conclusion that pAUK1 is identical to the 5' UTR of ACaM-2 and that the 5' UTR of ACaM-2 is an independent cDNA artificially linked to A. thaliana calmodulin cDNA.