Neighbor-joining tree representing alignment
of apyrases from selected sources. Sixteen partial sequences of plant
apyrases and the yeast protein GDA1 were aligned for analysis. The
apyrases fall into five distinct subfamilies. Mtapy1, Mtapy3,
Mtapy4, a newly identified EST from M. truncatula,
MtEST (GenBank accession no. AJ388942), LNP (accession no. AF139807),
and GS52 (accession no. AF207688; Day et al., 2000) fall into the first
class. Mtapy2 was found to fall into subfamily 2, along with
an Arabidopsis apyrase (accession no. AF156783; the second Arabidopsis
apyrase [accession no. AF141671] falls in a similar position, not
shown), and an EST from cotton, GhEST (accession no. AI729322).
Additional sequences include G. soja GS50 (accession no.
AF207687; Day et al., 2000), D. biflorus Dbapyrase
(accession no. AF156781), potato apyrase (accession no. U58597), tomato
EST cLED13N21 (accession no. AI488720), rice OsEST, (accession no.
AU065811), and the S. cerevisiae GDA1 (accession no.
6320793).