New England Biolabs, Inc.

William E Jack

Francine B Perler

Donald G Comb

Rebecca B Kucera

Ming-Qun Xu

Robert A Hodges

Christopher J Noren

Ira Schildkraut

Eric E Adam

Maurice W Southworth

Julie Forney Menin

Shaorong S Chong

The present invention relates to the use of site-specific nucleic acid nicking enzymes to create single-stranded regions in duplex nucleic acids. Such single-stranded regions can take the form of gaps interior to the duplex, or terminal single-stranded regions. Single-stranded termini can be crafted to allow linkage of various elements via base-pairing with elements containing a complementary single-stranded region. This joining is useful, for example, in an ordered, oriented assembly of DNA modules to create cloning or expression vectors. This joining is also useful in attaching detection probes and purifying DNA molecules containing the single-stranded region. Gaps are useful in similar applications, including attaching detection or purification probes.

Use of site-specific nicking endonucleases to create single-stranded regions and applications thereof

The present invention is directed to modified proteins and methods of their production. The modified proteins comprise a controllable intervening protein sequence (CIVPS) inserted into or adjacent a target protein, the CIVPS being capable of excision from or cleavage of the modified protein under predetermined conditions in cis or in trans, i.e., increase in temperature, exposure to light, unblocking of amino acid residues by dephosphorylation, treatment with chemical reagents or deglycosylation. If desired, the modified protein can be subjected to these conditions. The CIVPS may also be inserted into a region that substantially inactivates target protein activity. The CIVPS may be used in a number of applications including purification of the target protein in a one-step protocol.

Modified proteins comprising controllable intervening protein sequences

Recombinant DNA polymerases from archaebacteria as well as isolated DNA coding for such polymerases are provided. The isolated DNA is obtained by use or DNA or antibody probes prepared from the DNA encoding T. litoralis DNA polymerase and the T. litoralis DNA polymerase respectively. Also provided are methods for producing recombinant archaebacteria thermostable DNA polymerase and methods for enhancing the expression of such polymerases by identifying, locating and removing introns from within the DNA coding for such DNA polymerases.

Recombinant thermostable DNA polymerase from archaebacteria

Recombinant DNA polymerases from archaebacteria as well as isolated DNA coding for such polymerases are provided. The isolated DNA is obtained by use of DNA or antibody probes prepared from the DNA encoding T. litoralis DNA polymerase and the T. litoralis DNA polymerase respectively. Also provided are methods for producing recombinant archaebacteria thermostable DNA polymerase and methods for enhancing the expression of such polymerases by identifying, locating and removing introns from within the DNA coding for such DNA polymerases.

The present invention is directed to modified proteins and methods of their production. The modified proteins comprise a controllable intervening protein sequence (CIVPS) inserted into a target protein, the CIVPS being capable of excision from the modified protein under predetermined conditions, i.e., increase in temperature, exposure to light, unblocking of amino acid residues by dephosphorylation or deglycosylation. If desired, the modified protein can be subjected to these conditions. The CIVPS may also be inserted into a region that substantially inactivates target protein activity.

Modification of protein by use of a controllable interveining protein

Recombinant DNA polymeraset from archaebacteria as well as isolated DNA coding for such polymeraset are provided. The isolated DNA is obtained by use of DNA or antibody probet prepared from the DNA encoding T. litoralis DNA polymerate and the T. litoralis DNA polymerate respectively. Also provided are meshocs for producing recombinant archaebacteria thermostable DNA polymerase and methods for enhancing the expression of such polymeraset by identifying, locating and removing introns from within the DNA coding for such DNA polymerases.

There is provided an extremely thermostable enzyme obtainable from Thermococcus litoralis. The thermostable enzyme has a molecular weight of about 90,000-95,000 daltons, a half-life of about 60 minutes at 100.degree. C. in the absence of stabilizer, and a half-life of about 95 minutes at 100.degree. C. in the presence of stabilizer, such as octoxynol (TRITON X-100) or bovine serum albumin. The thermostable enzyme possesses a 3'-5' proofreading exonuclease activity. The thermostable enzyme may be native or recombinant and may be used for second-strand cDNA synthesis in cDNA cloning, DNA sequencing, and DNA amplification.

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Wenham, MA, United States of America

William E Jack