title: A global approach to identify novel broad-spectrum antibacterial targets among proteins of unknown function.
abstract: Attempted allelic replacement of 144 Streptococcus pneumoniae open reading frames of previously uncharacterized function led to the identification of 36 genes essential for growth under laboratory conditions. Of these, 14 genes (obg, spoIIIJ2, trmU, yacA, yacM, ydiC, ydiE, yjbN, yneS, yphC, ysxC, ytaG, yloI and yxeH4) were also essential in Staphylococcus aureus and Haemophilus influenzae or Escherichia coli, 2 genes (yrrK and ydiB) were only essential in H. influenzae as well as S. pneumoniae and 8 genes were necessary for growth of S.pneumoniae and S. aureus and did not have a homolog in H. influenzae(murD2, ykqC, ylqF, yqeH, ytgP, yybQ) or were not essential in that organism (yqeL, yhcT). The proteins encoded by these genes could represent good targets for novel antibiotics covering different therapeutic profiles. The putative functions of some of these essential proteins, inferred by bioinformatic analysis, are presented. Four mutants, with deletions of loci not essential for in vitro growth, were found to be severely attenuated in a murine respiratory tract infection model, suggesting that not all targets for antibacterial therapeutics are revealed by simple in vitro essentiality testing. The results of our experiments together with those collated from previously reported studies including Bacillus subtilis, E. coli and Mycoplasma sp. demonstrate that gene conservation amongst bacteria does not necessarily indicate that essentiality in one organism can be extrapolated to others. Moreover, this study demonstrates that different experimental procedures can produce apparently contradictory results.
authors.affiliation: Microbial, Musculoskeletal and Proliferative Diseases CEDD, Collegeville, PA 17426, USA. magdalena_zalacain-1@gsk.com
authors.forename: Magdalena
authors.initials: M
authors.lastname: Zalacain
authors.forename: Sanjoy
authors.initials: S
authors.lastname: Biswas
authors.forename: Karen A
authors.initials: KA
authors.lastname: Ingraham
authors.forename: Jennifer
authors.initials: J
authors.lastname: Ambrad
authors.forename: Alexander
authors.initials: A
authors.lastname: Bryant
authors.forename: Alison F
authors.initials: AF
authors.lastname: Chalker
authors.forename: Serban
authors.initials: S
authors.lastname: Iordanescu
authors.forename: Jing
authors.initials: J
authors.lastname: Fan
authors.forename: Frank
authors.initials: F
authors.lastname: Fan
authors.forename: R Dwayne
authors.initials: RD
authors.lastname: Lunsford
authors.forename: Karen
authors.initials: K
authors.lastname: O'Dwyer
authors.forename: Leslie M
authors.initials: LM
authors.lastname: Palmer
authors.forename: Chi
authors.initials: C
authors.lastname: So
authors.forename: Daniel
authors.initials: D
authors.lastname: Sylvester
authors.forename: Craig
authors.initials: C
authors.lastname: Volker
authors.forename: Patrick
authors.initials: P
authors.lastname: Warren
authors.forename: Damien
authors.initials: D
authors.lastname: McDevitt
authors.forename: James R
authors.initials: JR
authors.lastname: Brown
authors.forename: David J
authors.initials: DJ
authors.lastname: Holmes
authors.forename: Martin K R
authors.initials: MK
authors.lastname: Burnham
mesh_terms: D000483:Alleles; D000818:Animals; D001426:Bacterial Proteins / Q000187:drug effects / Q000235:genetics / Q000378:metabolism*; D019295:Computational Biology / Q000379:methods*; D004195:Disease Models, Animal; D015964:Gene Expression Regulation, Bacterial; D020043:Genes, Essential; D016680:Genome, Bacterial; D006193:Haemophilus influenzae / Q000187:drug effects / Q000235:genetics / Q000254:growth & development; D006801:Humans; D008297:Male; D051379:Mice; D008808:Mice, Inbred CBA; D016296:Mutagenesis; D011018:Pneumonia, Pneumococcal / Q000382:microbiology / Q000503:physiopathology; D011704:Pyelonephritis / Q000382:microbiology / Q000503:physiopathology; D011995:Recombination, Genetic; D012141:Respiratory Tract Infections / Q000382:microbiology / Q000503:physiopathology; D013203:Staphylococcal Infections / Q000382:microbiology / Q000503:physiopathology; D013211:Staphylococcus aureus / Q000187:drug effects / Q000235:genetics / Q000254:growth & development / Q000472:pathogenicity; D013296:Streptococcus pneumoniae / Q000187:drug effects* / Q000254:growth & development / Q000472:pathogenicity
chemical_list: D001426:Bacterial Proteins