It is shown that wild carrot cells contain both a bifunctional DHFR-TS (EC 2.1.1.45) and a monofunctional DHFR (EC 1.5.1.3). The bifunctional protein was present as the major DHFR fraction (80%) eluted from MTX-Sepharose. SDS-PAGE and immunoblot experiments showed that wild and domesticated carrot DHFR-TS have the same molecular mass (about 58 kDa). The immunochemical analysis showed the occurrence of the 58 kDa polypeptide also in the Nicotiana plumbaginifolia MTX-Sepharose fraction, whereas a band of about 50 kDa was recognized in Oryza sativa. DHFR and TS activities were present in both purified fractions. These data indicate that the bifunctional DHFR-TS is ubiquitous in plant cells.
Biochemical evidence for the presence of a bifunctional dihydrofolate reductase-thymidylate synthase in plant species
BALESTRAZZI, ALMA;CARBONERA, DANIELA;CELLA, RINO
1995-01-01
Abstract
It is shown that wild carrot cells contain both a bifunctional DHFR-TS (EC 2.1.1.45) and a monofunctional DHFR (EC 1.5.1.3). The bifunctional protein was present as the major DHFR fraction (80%) eluted from MTX-Sepharose. SDS-PAGE and immunoblot experiments showed that wild and domesticated carrot DHFR-TS have the same molecular mass (about 58 kDa). The immunochemical analysis showed the occurrence of the 58 kDa polypeptide also in the Nicotiana plumbaginifolia MTX-Sepharose fraction, whereas a band of about 50 kDa was recognized in Oryza sativa. DHFR and TS activities were present in both purified fractions. These data indicate that the bifunctional DHFR-TS is ubiquitous in plant cells.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
