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Two full length cDNA clones encoding uricase Ⅱ were isolated by plaque hybridization of a nodule cDNA library of Canavalia lineata with a uricase Ⅱ cDNA clone from soybean as a probe. Clone pcCINUO-01 was consisted of 1,611 bp with one open reading frame (ORF) of 924 nucleotides (NT), while clone pcCINUO-02 was consisted of 1,024 bp with one ORF of 903 NT. Nucleotide sequences for ORFs of the two clones showed 88.9% and 89.3% homology, respectively, to that of soybean uricase Ⅱ. Deduced amino acid sequence homologies to soybean uricase Ⅱ were 84.1% and 85.4%, respectively. At 313 NT downstream of the termination codon in pcCINUO-01, putative signal (AATAAA) for poly(A) addition was found, and 17 residues of poly(A) was found further downstream of 21 NT. The peroxisome-targeting signal (Ser-Lys-Leu) was also found at the carboxyl terminal of the deduced amino acid sequences for both ORFs. Deduced amino acid composition of pcCINUO-01 and pcCINUo-02 shows that the ratios of basic amino acids (Arg, His, Lys) and of pcCINUO-01 and pcCINUO-02 shows that the ratios of basic amino acids (Arg, His, Lys) and acidic amino acids (Asp, Clu) are 46 to 35 and 47 to 35, respectively. This amino acid composition indicates a basic nature of uricase Ⅱenzyme. According to Northern analysis of different organs, uricase Ⅱ gene was expressed only in root nodule. Genomic hybridization also revealed that the uricase Ⅱ gene may be present as a small multigene family on the genome of C. lineata.
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