Antibiotic Biosynthesis

Most clinically used antibiotics are based upon natural products. The β-lactams, including the penicillin, cephalosporin, clavam, and carbapenem antibiotics are amongst the most important therapeutic agents in current use. However, the accelerated emergence of bacteria that are resistant to multiple antibiotic types now appears as the most serious threat in the treatment of infectious diseases.
There are no commercially viable syntheses for these antibiotics, therefore all cephalosporin and most penicillin antibiotics are produced by complex and expensive synthetic modifications of fermented products. We are interested in studying the biosynthetic pathways to these compounds with a view to developing routes to improved antibiotics and to study the unusual chemistry of these reactions.

Penicillins and cephalosporins
Biosynthesis of the bicyclic nucleus of penicillins and cephalosporins involve common steps leading to isopenicillin N (IPN). After isomersation of IPN, cephalosporins are produced by the expansion of the five-membered heterocyclic ring. The first structural insights into the biosynthetic machinery of β-lactam antibiotics came from our studies on IPN synthase (IPNS) and deacetoxycephalosporin C synthase (DAOCS), the key oxygenase enzymes responsible for catalysis of the committed steps in the biosynthesis penicillins and cephalosporins, respectively. IPNS and DAOCS are interesting also because of the unusual chemistry that they catalyse.

Ribbon diagram of deacetoxycephalosporin C synthase (DAOCS) from Streptomyces clavuligerus with 2-oxoglutarate as yellow sticks and Fe(II) as a green sphere.

Ribbon diagram of deacetoxycephalosporin C synthase (DAOCS) from Streptomyces clavuligerus with 2-oxoglutarate as yellow sticks and Fe(II) as a green sphere.

Clavulanic acid
Clavulanic acid (CA) is the most important clinically used inhibitor of β-lactamases, which mediate bacterial resistance to penicillin-type antibiotics. CA is produced by fermentation because no asymmetric synthesis has yet been reported. We are studying the biosynthesis of CA with the general aim to improve production and/or to design modified pathways for the production of novel antibiotics. Crystallographic studies have resulted in structure determination of several enzymes from the pathway.

Publications

  • [DOI] K. Valegard, A. Iqbal, N. J. Kershaw, D. Ivison, C. Genereux, A. Dubus, C. Blikstad, M. Demetriades, R. J. Hopkinson, A. J. Lloyd, D. I. Roper, C. J. Schofield, I. Andersson, and M. A. Mcdonough, “Structural And Mechanistic Studies Of The Orf12 Gene Product From The,” Acta Crystallographica Section D-Biological Crystallography, vol. 69, pp. 1567-1579, 2013.
    [Bibtex] 
    @ARTICLE{14,
author  = "Valegard, Karin and Iqbal, Aman and Kershaw, Nadia J. and Ivison, David and Genereux, Catherine and Dubus, Alain and Blikstad, Cecilia and Demetriades, Marina and Hopkinson, Richard J. and Lloyd, Adrian J. and Roper, David I. and Schofield, Christopher J. and Andersson, Inger and Mcdonough, Michael A.",
title  = "Structural And Mechanistic Studies Of The Orf12 Gene Product From The",
journal  = "Acta Crystallographica Section D-Biological Crystallography",
volume  = "69",
doi  = {10.1107/S0907444913011013},
year  = {2013},
pages  = {1567--1579},
}
  • [DOI] A. K. Mackenzie, K. Valegard, A. Iqbal, M. E. C. Caines, N. J. Kershaw, S. E. Jensen, C. J. Schofield, and I. Andersson, “Crystal Structures Of An Oligopeptide-Binding Protein From The,” Journal Of Molecular Biology, vol. 396, iss. 2, pp. 332-344, 2010.
    [Bibtex] 
    @ARTICLE{6,
author  = "Mackenzie, Alasdair K. and Valegard, Karin and Iqbal, Aman and Caines, Matthew E. C. and Kershaw, Nadia J. and Jensen, Susan E. and Schofield, Christopher J. and Andersson, Inger",
title  = "Crystal Structures Of An Oligopeptide-Binding Protein From The",
journal  = "Journal Of Molecular Biology",
volume  = "396",
number  = "2",
doi  = {10.1016/j.jmb.2009.11.045},
year  = {2010},
pages  = {332--344},
}
  • [DOI] A. K. Mackenzie, N. J. Kershaw, H. Hernandez, C. V. Robinson, C. J. Schofield, and I. Andersson, “Clavulanic Acid Dehydrogenase: Structural And Biochemical Analysis Of,” Biochemistry, vol. 46, iss. 6, pp. 1523-1533, 2007.
    [Bibtex] 
    @ARTICLE{7,
author  = "Mackenzie, Alasdair K. and Kershaw, Nadia J. and Hernandez, Helena and Robinson, Carol V. and Schofield, Christopher J. and Andersson, Inger",
title  = "Clavulanic Acid Dehydrogenase: Structural And Biochemical Analysis Of",
journal  = "Biochemistry",
volume  = "46",
number  = "6",
doi  = {10.1021/bi061978x},
year  = {2007},
pages  = {1523--1533},
}
  • [DOI] G. Cicero, C. Carbonera, K. Valegard, J. Hajdu, I. Andersson, and G. Ranghino, “Study Of The Oxidative Half-Reaction Catalyzed By A Non-Heme Ferrous,” International Journal Of Quantum Chemistry, vol. 107, iss. 6, pp. 1514-1522, 2007.
    [Bibtex] 
    @ARTICLE{8,
author  = "Cicero, Giancarlo and Carbonera, Chiara and Valegard, Karin and Hajdu, Janos and Andersson, Inger and Ranghino, Graziella",
title  = "Study Of The Oxidative Half-Reaction Catalyzed By A Non-Heme Ferrous",
journal  = "International Journal Of Quantum Chemistry",
volume  = "107",
number  = "6",
doi  = {10.1002/qua.21275},
year  = {2007},
pages  = {1514--1522},
}
  • [DOI] L. Oster, D. Lester, A. Van Scheltinga, M. Svenda, M. Van Lun, C. Genereux, and I. Andersson, “Insights Into Cephamycin Biosynthesis: The Crystal Structure Of Cmcl,” Journal Of Molecular Biology, vol. 358, iss. 2, pp. 546-558, 2006.
    [Bibtex] 
    @ARTICLE{9,
author  = "Oster, Lm and Lester, Dr and Van Scheltinga, At and Svenda, M and Van Lun, M and Genereux, C and Andersson, I",
title  = "Insights Into Cephamycin Biosynthesis: The Crystal Structure Of Cmcl",
journal  = "Journal Of Molecular Biology",
volume  = "358",
number  = "2",
doi  = {10.1016/j.jmb.2006.02.004},
year  = {2006},
pages  = {546--558},
}
  • I. Andersson, A. C. Terwisscha Van Scheltinga, G. Ranghino, and K. ValegåRd, “Deacetoxycephalosporin C Synthase.” Handbook Of Metalloproteins, 2006.
    [Bibtex] 
    @INCOLLECTION{15,
title  = "Deacetoxycephalosporin C Synthase",
author  = "Andersson, Inger and Terwisscha Van Scheltinga, Anke C and Ranghino, Graziella and ValegåRd, Karin",
publisher  = "Handbook Of Metalloproteins",
year  = {2006},
}
  • [DOI] D. R. Lester, A. Phillips, P. Hedden, and I. Andersson, “Purification And Kinetic Studies Of Recombinant Gibberellin Dioxygenases,” Bmc Plant Biology, vol. 5, 2005.
    [Bibtex] 
    @ARTICLE{10,
author  = "Lester, Diane R. and Phillips, Andy and Hedden, Peter and Andersson, Inger",
title  = "Purification And Kinetic Studies Of Recombinant Gibberellin Dioxygenases",
journal  = "Bmc Plant Biology",
volume  = "5",
doi  = {10.1186/1471-2229-5-19},
year  = {2005},
}
  • [DOI] D. Lester, L. Oster, M. Svenda, and I. Andersson, “Expression, Purification, Crystallization And Preliminary X-Ray,” Acta Crystallographica Section D-Biological Crystallography, vol. 60, pp. 1618-1621, 2004.
    [Bibtex] 
    @ARTICLE{12,
author  = "Lester, Dr and Oster, Lm and Svenda, M and Andersson, I",
title  = "Expression, Purification, Crystallization And Preliminary X-Ray",
journal  = "Acta Crystallographica Section D-Biological Crystallography",
volume  = "60",
doi  = {10.1107/S090744490401666X},
year  = {2004},
pages  = {1618--1621},
}
  • [DOI] K. Valegard, A. Van Scheltinga, A. Dubus, G. Ranghino, L. Oster, J. Hajdu, and I. Andersson, “The Structural Basis Of Cephalosporin Formation In A Mononuclear Ferrous,” Nature Structural & Molecular Biology, vol. 11, iss. 1, pp. 95-101, 2004.
    [Bibtex] 
    @ARTICLE{13,
author  = "Valegard, K and Van Scheltinga, Act and Dubus, A and Ranghino, G and Oster, Lm and Hajdu, J and Andersson, I",
title  = "The Structural Basis Of Cephalosporin Formation In A Mononuclear Ferrous",
journal  = "Nature Structural & Molecular Biology",
volume  = "11",
number  = "1",
doi  = {10.1038/nsmb712},
year  = {2004},
pages  = {95--101},
}
  • [DOI] L. Oster, A. Van Scheltinga, K. Valegard, A. Hose, A. Dubus, J. Hajdu, and I. Andersson, “Conformational Flexibility Of The C Terminus With Implications For,” Journal Of Molecular Biology, vol. 343, iss. 1, pp. 157-171, 2004.
    [Bibtex] 
    @ARTICLE{11,
author  = "Oster, Lm and Van Scheltinga, Act and Valegard, K and Hose, Am and Dubus, A and Hajdu, J and Andersson, I",
title  = "Conformational Flexibility Of The C Terminus With Implications For",
journal  = "Journal Of Molecular Biology",
volume  = "343",
number  = "1",
doi  = {10.1016/j.jmb.2004.07.049},
year  = {2004},
pages  = {157--171},
}
  • [DOI] I. Andersson, A. Van Scheltinga, and K. Valegard, “Towards New Beta-Lactam Antibiotics,” Cellular And Molecular Life Sciences, vol. 58, iss. 12-13, pp. 1897-1906, 2001.
    [Bibtex] 
    @ARTICLE{0,
author  = "Andersson, I and Van Scheltinga, Act and Valegard, K",
title  = "Towards New Beta-Lactam Antibiotics",
journal  = "Cellular And Molecular Life Sciences",
volume  = "58",
number  = "12-13",
doi  = {10.1007/PL00000825},
year  = {2001},
pages  = {1897--1906},
}
  • A. Van Scheltinga, K. Valegard, S. Ramaswamy, J. Hajdu, and I. Andersson, “Multiple Isomorphous Replacement On Merohedral Twins: Structure,” Acta Crystallographica Section D-Biological Crystallography, vol. 57, pp. 1776-1785, 2001.
    [Bibtex] 
    @ARTICLE{1,
author  = "Van Scheltinga, Act and Valegard, K and Ramaswamy, S and Hajdu, J and Andersson, I",
title  = "Multiple Isomorphous Replacement On Merohedral Twins: Structure",
journal  = "Acta Crystallographica Section D-Biological Crystallography",
volume  = "57",
year  = {2001},
pages  = {1776--1785},
}
  • [DOI] M. Lloyd, H. Lee, K. Harlos, Z. Zhang, J. Baldwin, C. Schofield, J. Charnock, C. Garner, T. Hara, A. Van Scheltinga, K. Valegard, J. Viklund, J. Hajdu, I. Andersson, A. Danielsson, and R. Bhikhabhai, “Studies On The Active Site Of Deacetoxycephalosporin C Synthase,” Journal Of Molecular Biology, vol. 287, iss. 5, pp. 943-960, 1999.
    [Bibtex] 
    @ARTICLE{2,
author  = "Lloyd, Md and Lee, Hj and Harlos, K and Zhang, Zh and Baldwin, Je and Schofield, Cj and Charnock, Jm and Garner, Cd and Hara, T and Van Scheltinga, Act and Valegard, K and Viklund, Jac and Hajdu, J and Andersson, I and Danielsson, A and Bhikhabhai, R",
title  = "Studies On The Active Site Of Deacetoxycephalosporin C Synthase",
journal  = "Journal Of Molecular Biology",
volume  = "287",
number  = "5",
doi  = {10.1006/jmbi.1999.2594},
year  = {1999},
pages  = {943--960},
}
  • K. Valegard, A. Van Scheltinga, M. Lloyd, T. Hara, S. Ramaswamy, A. Perrakis, A. Thompson, H. Lee, J. Baldwin, C. Schofield, J. Hajdu, and I. Andersson, “Structure Of A Cephalosporin Synthase,” Nature, vol. 394, iss. 6695, pp. 805-809, 1998.
    [Bibtex] 
    @ARTICLE{3,
author  = "Valegard, K and Van Scheltinga, Act and Lloyd, Md and Hara, T and Ramaswamy, S and Perrakis, A and Thompson, A and Lee, Hj and Baldwin, Je and Schofield, Cj and Hajdu, J and Andersson, I",
title  = "Structure Of A Cephalosporin Synthase",
journal  = "Nature",
volume  = "394",
number  = "6695",
year  = {1998},
pages  = {805--809},
}
  • [DOI] P. Roach, I. Clifton, V. Fulop, K. Harlos, G. Barton, J. Hajdu, I. Andersson, C. Schofield, and J. Baldwin, “Crystal-Structure Of Isopenicillin N-Synthase Is The First From A New,” Nature, vol. 375, iss. 6533, pp. 700-704, 1995.
    [Bibtex] 
    @ARTICLE{4,
author  = "Roach, Pl and Clifton, Ij and Fulop, V and Harlos, K and Barton, Gj and Hajdu, J and Andersson, I and Schofield, Cj and Baldwin, Je",
title  = "Crystal-Structure Of Isopenicillin N-Synthase Is The First From A New",
journal  = "Nature",
volume  = "375",
number  = "6533",
doi  = {10.1038/375700a0},
year  = {1995},
pages  = {700--704},
}
  • [DOI] N. Morgan, I. Pereira, I. Andersson, R. Adlington, J. Baldwin, S. Cole, N. Crouch, and J. Sutherland, “Substrate-Specificity Of Recombinant Streptomyces-Clavuligerus,” Bioorganic & Medicinal Chemistry Letters, vol. 4, iss. 13, pp. 1595-1600, 1994.
    [Bibtex] 
    @ARTICLE{5,
author  = "Morgan, N and Pereira, Iac and Andersson, Ia and Adlington, Rm and Baldwin, Je and Cole, Scj and Crouch, Np and Sutherland, Jd",
title  = "Substrate-Specificity Of Recombinant Streptomyces-Clavuligerus",
journal  = "Bioorganic & Medicinal Chemistry Letters",
volume  = "4",
number  = "13",
doi  = {10.1016/S0960-894X(01)80573-4},
year  = {1994},
pages  = {1595--1600},
}