Bariloche protein symposium argentine society for biochemistry and molecular biology

69
BIOCELL, 27 (Suppl. I), 2003
MI-P38.
INTERACTION OF P36 PROTEIN WITH Mycobacterium
tuberculosis PROTEOME
Klepp, Laura X.; Bigi, Fabiana; Gioffré, Andrea; Santangelo,
María de la Paz; Alito, Alicia E.; Caimi, Karina; Meikle, Virginia;
Zumárraga, Martín; Romano, María I.; Cataldi, Angel A.
Instituto de Biotecnología, CICVyA, INTA-Castelar, Buenos Aires,
Agentina. E-mail: [e-mail].
Tuberculosis, a chronic illness caused by Mycobacterium
tuberculosis, is still a major worldwide disease. According to the
World Health Organization, tuberculosis is a considerable public
health problem in Latin America, Asia and Africa.
P36 is a secreted 36 kDa protein with a central domain containing
several PGLTS repeats. This protein has been shown as associated
to virulence since the disruption of its gene impaired multiplication
of virulent M. tuberculosis and M. bovis BCG in cultured
macrophages and immunocompetent mice. In this study, to further
elucidate the function of P36, we searched for P36-binding proteins
by screening a M. tuberculosis DNA library with full-length P36
using a bacterial two-hybrid system. Two different genes were
obtained whose products interact specifically with P36. These
genes are Rv1417 and Rv2617c, which encoding for a possible
conserved membrane protein and probable transmembrane protein
respectively. The function of these proteins is currently unknown.
Bioinformatical analyses revealed some similarity to hypothetical
or membrane proteins from others bacterial species, e-g.
Corynebacterium ammoniagenes,  Streptomyces coelicolor and
Rhizobium meliloti. Interesting, there is a putative transport protein
from  Rhizobium meliloti similar to Rv2617c, suggesting that
Rv2617c could be involved in P36 transport.
MI-P39.
VP1: SEQUENCE VARIABILITY OF LAST FMDV
OUTBREAKS IN ARGENTINA
König G
1
, Gomez E
1
, Mazzuca G
2
, Piccone M
1
1
INTA-Castelar, 
2
SENASA. E-mail: [e-mail]
Foot and mouth disease virus (fmdv) belongs to the picornaviridae
family. The single stranded rna codes for a unique polyprotein
that is subsequently processed into different non-structural and
structural proteins (vp1-4). Among them, vp1 is the mainly exposed
one therefore it posses the major antigenic determinants and it is
also the most variable of the structural proteins. Here we analyze
this variability of different isolates in four national outbreaks:
serotype o (1993-1994 and 2000);  serotype a (2000 and 2001). 28
sequences of vp1 a2001 were aligned and we found a nucleotide
difference, between pairs, from 0 to 3,86%. 11 isolates analyzed
of a2000, 5 of o2000 and 12 of o1993/4 resulted in a nucleotide
divergence up to 1,1; 0,63 and 2,91 respectibly. When we study
differences in the amino acid sequence they slightly grew to 6,1;
2,3; 0,9 and 3,3% in the same order used above. Taking the four
groups together, we found 103 nucleotide changes. 54% of them
are synonymous changes and 46% are non synonymous, however
more than a half of them were non conservative (57%). If we
analyze the antigenic sites described for both serotype we found
that, not surprisingly, 54% of the changes were located in these
regions of the genome although they represent just 1/5 of their
total length. A detailed analysis of the variability of different
isolates in the same outbreak in combination with the phylogenetic
analysis can give us some hint of the evolution of the virus in a
short-term period.
MI-P40.
IDENTIFICATION AND  CHARACTERIZATION  OF 
β-
OXIDATION PATHWAY REQUIRED FOR
TESTOSTERONE DEGRADATION IN COMAMONAS
TESTOSTERONI
Linares M, Pruneda Paz JL, and Genti-Raimondi S.
Dpto. de Bioquímica Clínica. Fac. Ciencias Químicas.UNC. Haya
de la Torre y Medina Allende. Ciudad Universitaria. Córdoba.
5000. Argentina. E-mail: [e-mail]
We have identified a new steroid inducible gene in C. testosteroni,
designated teiR (testosterone inducible Regulator) that is required
for testosterone degradation. Nucleotide sequence analysis of teiR
predicts a 391-amino-acid protein, which bears homology between
residues 327 and 380 to the LuxR helix-turn-helix DNA binding
domain and between 192-227 residues to the PAS sensor domain.
In addition, three ORFs transcribed in the same direction sequence
that  teiR  were cloned. These genes encode proteins with high
similarity to 
βketo-thiolase (tekt), MaoC acyl dehydratase and 3-
oxoacyl reductase enzymes respectively, all of them involved in a
β-oxidation pathway. Analysis of the gene expression indicated
that at least teiR and tekt genes are tightly controlled at the
transcriptional level by testosterone. teiR-disrupted mutant is
completely unable to use testosterone as the sole carbon and energy
source. Also, the expression of several steroid-inducible genes was
abolished in this mutant. Moreover, when teiR was provided in
trans to the TeiR-disrupted strain, the transcription level of these
genes was restored. These results indicate that TeiR positively
regulates the transcription of genes involved in the initial enzymatic
steps of steroid degradation as well as the 
β-oxidation pathway
and these genes are essential for the complete mineralization of
testosterone.
MI-P41.
PSYCHROTOLERANT HYDROCARBON-DEGRADING
RHODOCOCCUS STRAINS ISOLATED FROM
ANTARCTICA
Ruberto, Lucas
1
; Vazquez, Susana
1
; Mac Cormack, Walter
2
1
Facultad de Farmacia y Bioquímica, UBA. 
2
Instituto Antártico
Argentino. E-mail: [e-mail]
When hydrocarbons are spilled on pristine soils, bioaugmentation
represent the most promising option to reduce hydrocarbon
contamination. In these cases, temperature is one of the most
important factor affecting biodegradation activity and only
psychrotolerant microorganisms are adequate for designing
bioremediation processes in extremely cold areas as the Antarctic
continent. Seeing as Rhodococcus strains seem to be one of the
most efficient hydrocarbon-degrading bacterial group in Antarctica,
we reported here the taxonomic and physiological characterization
of three Antarctic Rhodococcus strains (ADH, DM1-21 and DM1-
22) with hydrocarbon degradation activity. Isolation was made from
polluted soils from Jubany and Marambio stations. Rhodococcus
strains were characterized by biochemical and molecular test. ADH
and DM1-22 were related to R. erythropolis whereas DM1-21
was related to R. erythreus. Strains showed high hydrocarbon-
degrading capacity on aliphatics and complex mixtures but not on
aromatic hydrocarbons. Specific growth rate in cultures with n-
hexadecane ranged between 0.028 h
-1
 (ADH) and 0.038 h
-1
 (DM1-
21) and 84-86% of the hydrocarbon was removed in all cases.
Bioremediation performed in microcosms systems in Antarctica
showed that the presence of the isolated strains enhances the
biodegradation activity of the natural microflora. These results
showed that the isolated psychrotolerant Antarctic Rhodococcus
are useful for application in hydrocarbon bioremediation processes
in Antarctica and other cold areas.

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