Autor(es):
Rodrigues, Fernando José dos Santos 
; Zeeman, Anne-Marie ; Cardoso, M. Helena ; Sousa, Maria João ; Steensma, H. Yde ; Leão, Cecília
Data: 2004
Identificador Persistente: http://hdl.handle.net/1822/1774
Origem: RepositóriUM - Universidade do Minho
Assunto(s): Zygosaccharomyces bailii; Acetic acid metabolism; Acetyl-CoA synthetase
Descrição
A gene homologous to Saccharomyces cerevisiae ACS genes, coding for acetyl-CoA
synthetase, has been cloned from the yeast Zygosaccharomyces bailii ISA 1307, by
using reverse genetic approaches. A probe obtained by PCR amplification from Z.
bailii DNA, using primers derived from two conserved regions of yeast ACS proteins,
RIGAIHSVVF (ScAcs1p; 210–219) and RVDDVVNVSG (ScAcs1p; 574–583), was
used for screening a Z. bailii genomic library. Nine clones with partially overlapping
inserts were isolated. The sequenced DNA fragment contains a complete ORF of
2027 bp (ZbACS2) and the deduced polypeptide shares significant homologies with
the products of ACS2 genes from S. cerevisiae and Kluyveromyces lactis (81%
and 82% identity and 84% and 89% similarity, respectively). Phylogenetic analysis
shows that the sequence of Zbacs2 is more closely related to the sequences from
Acs2 than to those from Acs1 proteins. Moreover, this analysis revealed that the
gene duplication producing Acs1 and Acs2 proteins has occurred in the common
ancestor of S. cerevisiae, K. lactis, Candida albicans, C. glabrata and Debaryomyces
hansenii lineages. Additionally, the cloned gene allowed growth of S. cerevisiae Scacs2
null mutant, in medium containing glucose as the only carbon and energy source,
indicating that it encodes a functional acetyl-CoA synthetase. Also, S. cerevisiae cells
expressing ZbACS2 have a shorter lag time, in medium containing glucose (2%,
w/v) plus acetic acid (0.1–0.35%, v/v). No differences in cell response to acetic acid
stress were detected both by specific growth and death rates. The mode of regulation
of ZbACS2 appears to be different from ScACS2 and KlACS2, being subject to
repression by a glucose pulse in acetic acid-grown cells. The nucleotide sequence
of a common 5269 bp fragment has been deposited in the EMBL Data Library under
Accession No. AJ314837.
