ÿþ<HTML><HEAD><TITLE>25º Congresso Brasileiro de Microbiologia </TITLE><link rel=STYLESHEET type=text/css href=css.css></HEAD><BODY aLink=#ff0000 bgColor=#FFFFFF leftMargin=0 link=#000000 text=#000000 topMargin=0 vLink=#000000 marginheight=0 marginwidth=0><table align=center width=700 cellpadding=0 cellspacing=0><tr><td align=left bgcolor=#cccccc valign=top width=550><font face=arial size=2><strong><font face=Verdana, Arial, Helvetica, sans-serif size=3><font size=1>25º Congresso Brasileiro de Microbiologia </font></font></strong><font face=Verdana size=1><b><br></b></font><font face=Verdana, Arial,Helvetica, sans-serif size=1><strong> </strong></font></font></td><td align=right bgcolor=#cccccc valign=top width=150><font face=arial size=2><strong><font face=Verdana, Arial, Helvetica, sans-serif size=1><font size=1>ResumoID:916-1</font></em></font></strong></font></td></tr><tr><td colspan=2><br><br><table align=center width=700><tr><td>Área: <b>Microbiologia Geral ( Divisão H )</b><p align=justify><strong>SEQUENCE ANALYSIS AND MOLECULAR CLONING OF A STREPTOCOCCUS MUTANS ORTHOPHOSPHATE PERMEASE.</strong></p><p align=justify><b><u>Daniela Eleuterio da Luz </u></b> (<i>ICBII-USP</i>); <b>Roberto Nepomuceno de Souza Lima </b> (<i>ICBII-USP</i>); <b>Beny Spira </b> (<i>ICBII-USP</i>); <b>Luis Carlos de Souza Ferreira </b> (<i>ICBII-USP</i>); <b>Rita de Cássia Café Ferreira </b> (<i>ICBII-USP</i>)<br><br></p><b><font size=2>Resumo</font></b><p align=justify class=tres><font size=2><p>Inorganic phosphate (Pi) is an ubiquitous molecule, present in all living beings and with important roles in different biological molecules, such as nucleics acids , phospholipids and ATP. In <i>Escherichia coli  </i>and other microorganisms phosphate  is taken up through two main specific carriers, a low affinity system, represented by Pit and a high-affinity Pst system which belongs to the family of ABC-transportes and is induced under phosphate starvation. The aim of the present study was the <i>in silico </i>characterization of the<i> Streptococcus mutans</i> <i>pst </i>operon and cloning of the Phosphate-biding protein PstS. Analysis of the genome sequence of the <i>S. mutans </i>UA159 revealed an operon with six genes encompassing <i>pstS </i>(phosphate-binding protein)<i>, pstC </i>and<i> pstC1</i> (transmembrane proteins),  <i>pstB </i>and<i> SM1134 </i>(ATP-binding proteins) and<i> phoU </i>(function unknown). The PstS amino acid sequence shared the highest similarity with <i>Streptococcus sanguinis </i>(80% identity) ortholog, although there was no evidence of horizontal gene transfer between the two species. <i>Streptococcus mutans</i> <i>pstS </i>gene was amplified and cloned in <i>Escherichia coli</i> expression vectors (pQE-30 and pET28a),  but the recombinant protein could not expressed in this bacterium. Successful expression of the <i>Streptococcus mutans </i>PstS was achieved in <i>Bacillus subtilis</i>, using vector pHT08, which allowed the intracellular accumulation of the recombinant protein. BALB/c mice inoculated with the recombinant protein raised specific anti-PstS antibodies that recongnized the native protein expressed in <i>S. mutans</i> strains. Identification and cloning of the Pst proteins will contribute to the understanding of the physiological role of the Pst system in the nutrition strategies and patogenicity of <i>Streptococcus mutans.</i></p> This work was supported by FAPESP and CNPq. <br> </font></p><br><b>Palavras-chave: </b>&nbsp;ABC transporter, inorganic phosphate uptake, Heterologous protein expression, Pst system, Streptococcus mutans</td></tr></table></tr></td></table></body></html>