A global approach to identify novel broad-spectrum antibacterial targets among proteins of unknown function.
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.
Zalacain
Magdalena
M
Microbial, Musculoskeletal and Proliferative Diseases CEDD, Collegeville, PA 17426, USA. magdalena_zalacain-1@gsk.com
Biswas
Sanjoy
S
Ingraham
Karen A
KA
Ambrad
Jennifer
J
Bryant
Alexander
A
Chalker
Alison F
AF
Iordanescu
Serban
S
Fan
Jing
J
Fan
Frank
F
Lunsford
R Dwayne
RD
O'Dwyer
Karen
K
Palmer
Leslie M
LM
So
Chi
C
Sylvester
Daniel
D
Volker
Craig
C
Warren
Patrick
P
McDevitt
Damien
D
Brown
James R
JR
Holmes
David J
DJ
Burnham
Martin K R
MK
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
D001426:Bacterial Proteins