Abstract: A recombinant vector adapted for transformation of a suitable microorganism host to produce and secrete streptokinase. The recombinant vector comprises a plasmid into which a polydeoxyribonucleotide fragment from Streptococcus equisimilis H46A which codes for streptokinase synthesis and secretion has been inserted. The transformant microorganism including this recombinant plasmid vector produces streptokinase suitable for clinical fibrinolytic usage after purification.

Abstract: A new class of DNA vectors, each comprising two replication systems; a first origin of replication resulting in a low copy number and stable inheritance of the plasmid, and a second, high copy number, origin of replication at which replication is directly controllable such that, when host cells carrying the vector are propagated under a first set of conditions, replication takes mainly from the low copy number origin, and that when said cells are propagated under a second set of conditions, replication takes place also from the high copy number origin to produce a high yield of gene product. The controllable origin of replication may be under the control of a natural promoter of RNA transcription or a substitute promoter such as the PL promoter or lac promoter.

Abstract: Chromosomal DNA cassettes containing genes encoding either the DpnI or DpnII restriction endonucleases from Streptococcus pneumoniae are cloned into a streptococcal vector, pLS101. Large amounts of the restriction enzymes are produced by cells containing the multicopy plasmids, pLS202 and pLS207, and their derivatives pLS201, pLS211, pLS217, pLS251 and pLS252.

Abstract: This application describes a means to clone a functional gene for bacteriophage T7 RNA polymerase. Active T7 RNA polymerase is produced from the cloned gene, and a plasmid has been constructed that can produce the active enzyme in large amounts. T7 RNA polymerase transcribes DNA very efficiently and is highly selective for a relatively long promoter sequence. This enzyme is useful for synthesizing large amounts of RNA in vivo or in vitro, and is capable of producing a single RNA selectively from a complex mixture of DNAs. The procedure used to obtain a clone of the T7 RNA polymerase gene can be applied to other T7-like phages to obtain clones that produce RNA polymerases having different promoter specificities, different bacterial hosts, or other desirable properties. T7 RNA polymerase is also used in a system for selective, high-level synthesis of RNAs and proteins in suitable host cells.

Abstract: Disclosed is a method for identifying and isolating gene sequences coding for polypeptide sequences which result in specific functional activities or phenotypes, which may then be synthesized and assembled to form new proteins. The assembled protein may contain only amino acid sequences essential for specific functions, have a new quaternary structure resulting from addition of an amino acid sequence with oligomeric activity, or exhibit multiple activities. Also disclosed is a method for identifying, analyzing and synthesizing amino acid sequences with oligomeric activity which may be used to enhance or add a new activity to a protein.In one embodiment, the piece with oligomeric activity is fused onto a polypeptide with one or more additional activities. In another embodiment, this polypeptide sequence is hybridized with a second polypeptide consisting only of the sequence with oligomeric activity.

Abstract: This invention features a method of isolating a mutant strain of Escherichia coli, having a defective periplasmic protease, the method comprising the steps of: mutagenizing an E. coli cell, wherein the cell comprises: (a) an inner and an outer membrane, (b) a periplasmic space between the membranes, (c) a protein which in a first state is mobile, being able to move through the outer membrane and enter medium surrounding the cells, the protein in the first state being detectable in the medium, and in a second state is not mobile, remaining inside the cell, and (d) a periplasmic protease which converts the protein from the second state to the first state in the cell, and selecting a mutant cell which produces a reduced level of the detectable protein in the medium compared to the E. coli cell, wherein the mutant cell comprises the defective periplasmic protease.This invention also features mutant strains of E. coli having a defective periplasmic protease.

Abstract: A DNA sequence wherein a DNA segment coding for a signal peptide of the formula:M-R-S-F-L-L-L-A-L-C-F-L-P-L-A-A-L-Gis bound to the 5' end of a DNA segment coding for human lysozyme, a cell transformed with the above DNA sequence and a process for producing human lysozyme, which comprises cultivating the above cell accumulating human lysozyme in the culture and recovering the same are disclosed.The above techniques make the mass production of human lysozyme useful as pharmaceuticals possible. The present signal peptide is superior to that of hen egg white lysozyme for secretive production of human lysozyme.

Abstract: The present invention relates to the plasmid pTR2030 and derivatives thereof which confer phage resistance to group N streptococci. The invention further relates to microorganisms containing pTR2030 or a derivative thereof and to starter cultures containing the microorganisms.

Abstract: The plasmids pDR401 and pDR412 are disclosed which contain a selectable chloramphenicol resistance gene and which are able to replicate in both T. ferrooxidans and E. coli. A process for constructing the plasmids is also described.