Rhamnose Promoter Expression System

Abstract

The present invention relates to new vectors expressible in Pseudomonas comprising the rhaBAD promoter region of the L-rhamnose operon operably linked to a transcriptional unit comprising a) a nucleic acid sequence which is heterologous to said host b) a prokaryotic signal sequence operably linked to said nucleic acid sequence, whereas said prokaryotic signal sequence is selected from signal peptides of periplasmatic binding proteins for sugars, amino acids, vitamins and ions and, whereas the expression of said nucleic acid sequence is controlled by said promoter region. Also disclosed are: the use of said new vector for the regulated heterologous expression of a nucleic acid sequence in a Pseudomonas host cell; an isolated and purified nucleic acid sequence expressible in a Pseudomonas host cell comprising the promoter region of the L-rhamnose operon; and a method for producing a polypeptide in a host using said vector.

1 - 11 . (canceled) 
     
     
         12 . A vector for the expression of Fab fragments comprising the rhaBAD promoter region of the L-rhamnose operon operably linked to a transcriptional unit,
 wherein said rhaBAD promoter region and said operably linked transcriptional unit consists of SEQ ID NO. 4, a sequence complementary thereof and variants thereof.   
     
     
         13 . The vector of  claim 12 , wherein said vector is an autonomously or self-replicating plasmid, a cosmid, a phage, a virus or a retrovirus. 
     
     
         14 . A process comprising utilizing the vector of  claim 13 , for the regulated heterologous expression of a nucleic acid sequence in a prokaryotic host. 
     
     
         15 . The process comprising utilizing the vector of  claim 14 , wherein said nucleic acid sequence encodes for a polypeptide. 
     
     
         16 . The process comprising utilizing the vector of  claim 15 , wherein said polypeptide is a Fab fragment, wherein heavy and light chains of the Fab fragment are expressed in equal amounts. 
     
     
         17 - 20 . (canceled) 
     
     
         21 . An isolated and purified nucleic acid sequence operably linked to a transcriptional unit, wherein said rhaBAD promoter region and said operably linked transcriptional unit consists of SEQ ID NO 4, a sequence complementary thereof and variants thereof. 
     
     
         22 - 38 . (canceled)