• Biochemical characterization of ParI, an orphan C5-DNA methyltransferase from Psychrobacter arcticus 273-4 

      Grgic, Miriam; Williamson, Adele Kim; Bjerga, Gro Elin Kjæreng; Altermark, Bjørn; Leiros, Ingar (Journal article; Tidsskriftartikkel; Peer reviewed, 2018-05-25)
      <p>Cytosine-specific DNA methyltransferases are important enzymes in most living organisms. In prokaryotes, most DNA methyltransferases are members of the type II restriction-modification system where they methylate host DNA, thereby protecting it from digestion by the accompanying restriction endonucleases. DNA methyltransferases can also act as solitary enzymes having important roles in controlling ...
    • Cold shock induction of recombinant Arctic environmental genes 

      Bjerga, Gro Elin Kjæreng; Williamson, Adele Kim (Journal article; Tidsskriftartikkel; Peer reviewed, 2015-08-19)
      Background: Heterologous expression of psychrophilic enzymes in E. coli is particularly challenging due to their intrinsic instability. The low stability is regarded as a consequence of adaptation that allow them to function at low temperatures. Recombinant production presents a significant barrier to their exploitation for commercial applications in industry. <p>Methods: As part of an enzyme ...
    • Engineering low-temperature expression systems for heterologous production of cold-adapted enzymes 

      Bjerga, Gro Elin Kjæreng; Lale, Rahmi; Williamson, Adele Kim (Journal article; Tidsskriftartikkel; Peer reviewed, 2016-02-26)
      Production of psychrophilic enzymes in the commonly used mesophilic expression systems is hampered by low intrinsic stability of the recombinant enzymes at the optimal host growth temperatures. Unless strategies for low-temperature expression are advanced, research on psychrophilic enzymes may end up being biased toward those that can be stably produced in commonly used mesophilic host systems. Two ...
    • High quality draft genome sequence of Streptomyces sp. strain AW19M42 isolated from a sea squirt in Northern Norway 

      Bjerga, Gro Elin Kjæreng; Hjerde, Erik; De Santi, Concetta; Williamson, Adele Kim; Smalås, Arne O.; Willassen, Nils Peder; Altermark, Bjørn (Journal article; Tidsskriftartikkel; Peer reviewed, 2014)
    • A high-throughput, restriction-free cloning and screening strategy based on ccdB-gene replacement 

      Bjerga, Gro Elin Kjæreng; Lund, Bjarte Aarmo; Leiros, Hanna-Kirsti S. (Journal article; Tidsskriftartikkel; Peer reviewed, 2014)
      Background In high-throughput demanding fields, such as biotechnology and structural biology, molecular cloning is an essential tool in obtaining high yields of recombinant protein. Here, we address recently developed restriction-free methods in cloning, and present a more cost-efficient protocol that has been optimized to improve both cloning and clone screening. Results In our case study, ...
    • Investigating the role of residues W228 and Y233 in the structure and activity of the GIM-1 metallo-beta-lactamase. 

      Skagseth, Susann; Carlsen, Trine Josefine Olsen; Bjerga, Gro Elin Kjæreng; Spencer, James; Samuelsen, Ørjan; Leiros, Hanna-Kirsti S. (Journal article; Tidsskriftartikkel; Peer reviewed, 2015-12-07)
      Metallo--lactamases (MBLs) hydrolyze virtually all -lactam antibiotics, including penicillins, cephalosporins, and carbapenems. The worldwide emergence of antibiotic-resistant bacteria harboring MBLs poses an increasing clinical threat. The MBL German imipenemase-1 (GIM-1) possesses an active site that is narrower and more hydrophobic than the active sites of other MBLs. The GIM-1 active-site ...
    • Mutational analysis of the pro-peptide of a marine intracellular subtilisin protease supports its role in inhibition 

      Bjerga, Gro Elin Kjæreng; Larsen, Øivind; ARSIN, Hasan; Williamson, Adele Kim; Garcia-Moyano, Antonio; Leiros, Ingar; Puntervoll, Pål (Journal article; Tidsskriftartikkel, 2018-06-16)
      Intracellular subtilisin proteases (ISPs) have important roles in protein processing during the stationary phase in bacteria. Their unregulated protein degrading activity may have adverse effects inside a cell, but little is known about their regulatory mechanism. Until now, ISPs have mostly been described from <i>Bacillus</i> species, with structural data from a single homolog. Here, we study a ...
    • Structural and biochemical characterization of VIM-26 shows that Leu224 has implications for the substrate specificity of VIM metallo-β-lactamases 

      Leiros, Hanna-Kirsti S.; Edvardsen, Kine Susann Waade; Bjerga, Gro Elin Kjæreng; Samuelsen, Ørjan (Journal article; Tidsskriftartikkel; Peer reviewed, 2015-02-06)
      During the last decades antimicrobial resistance has become a global health problem. Metallo-β-lactamases (MBLs) which are broad-spectrum β-lactamases that inactivate virtually all β-lactams including carbapenems, are contributing to this health problem. In this study a novel MBL variant, termed VIM-26, identified in a Klebsiella pneumoniae isolate was studied. VIM-26 belongs to the Verona ...