Biochemical characterization of serine acetyl transferase and cysteine desulfhydrase from Leishmania major

MARCIANO DANIELA; SANTANA MARIANELA; SUAREZ MANTILLA BRIAN; SILBER ARIEL MARIANO; MARINO-BUSLJE CRISTINA; NOWIKI CRISTINA

MOLECULAR AND BIOCHEMICAL PARASITOLOGY

ELSEVIER SCIENCE BV

Año: 2010 vol. 173 p. 170 - 174

0166-6851

Cysteine metabolism exhibits atypical features in Leishmania parasites. The nucleotide sequence annotatedas LmjF32.2640 encodes a cysteine desulfhydrase, which specifically catalyzes the breakdown ofcysteine into pyruvate,NH3 andH2S. Like in other pathogens, this capacity might be associated with regulatorymechanisms to control the intracellular level of cysteine, a highly toxic albeit essential amino acid,in addition to generate pyruvate for energy production. Besides, our results provide the first insight intothe biochemical properties of Leishmania major serine acetyltransferase (SAT), which is likely involved inthe two routes for de novo synthesis of cysteine in this pathogen. When compared with other members ofSAT family, the N-terminal region of L. major homologue is uniquely extended, and seems to be essentialfor proper protein folding. Furthermore, unlike plant and bacterial enzymes, the carboxy-terminal-C10sequence stretch of L. major SAT appears not to be implicated in forming a tight bi-enzyme complex withcysteine synthase.