Saleem Khan

Summary

Affiliation: University of Pittsburgh
Country: USA

Publications

  1. ncbi request reprint Plasmid rolling-circle replication: recent developments
    S A Khan
    Department of Molecular Genetics and Biochemistry, University of Pittsburgh School of Medicine, Pittsburgh, PA 15261, USA
    Mol Microbiol 37:477-84. 2000
  2. pmc Alteration of microRNA profiles in squamous cell carcinoma of the head and neck cell lines by human papillomavirus
    Abigail I Wald
    Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
    Head Neck 33:504-12. 2011
  3. ncbi request reprint Plasmid rolling-circle replication: highlights of two decades of research
    Saleem A Khan
    Department of Molecular Genetics and Biochemistry, University of Pittsburgh School of Medicine, Pittsburgh, PA 15261, USA
    Plasmid 53:126-36. 2005
  4. doi request reprint Marked increase in biofilm-derived rough pneumococcal variants and rifampin-resistant strains not due to hex gene mutations
    M Catherine McEllistrem
    University of Pittsburgh, Department of Medicine, Pittsburgh, Pennsylvania, USA
    Microb Drug Resist 15:85-90. 2009
  5. pmc DNA helicase activity of PcrA is not required for the displacement of RecA protein from DNA or inhibition of RecA-mediated strand exchange
    Syam P Anand
    Department of Molecular Genetics and Biochemistry, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania 15261, USA
    J Bacteriol 189:4502-9. 2007
  6. ncbi request reprint Biochemical characterization of the Staphylococcus aureus PcrA helicase and its role in plasmid rolling circle replication
    Tseh Ling Chang
    Department of Molecular Genetics and Biochemistry, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania 15261, USA
    J Biol Chem 277:45880-6. 2002
  7. ncbi request reprint Detection of very high-level penicillin-resistant variants of the Tennessee (23 F)-4 clone via single and serial transformations with four serotype 19 A international pneumococcal clones
    M Catherine McEllistrem
    University of Pittsburgh School of Medicine, Pittsburgh, PA 15213 2582, USA
    Microb Drug Resist 11:271-8. 2005
  8. pmc Expedient placement of two fluorescent dyes for investigating dynamic DNA protein interactions in real time
    Sanford H Leuba
    Department of Cell Biology, University of Pittsburgh School of Medicine and Swanson School of Engineering, Petersen Institute of NanoScience and Engineering and University of Pittsburgh Cancer Institute, Pittsburgh, PA, 15213, USA
    Chromosome Res 16:451-67. 2008
  9. pmc Characterization of in vitro biofilm-associated pneumococcal phase variants of a clinically relevant serotype 3 clone
    M Catherine McEllistrem
    Division of Infectious Diseases, University of Pittsburgh School of Medicine, PA 15213 2582, USA
    J Clin Microbiol 45:97-101. 2007
  10. pmc A novel FtsZ-like protein is involved in replication of the anthrax toxin-encoding pXO1 plasmid in Bacillus anthracis
    Eowyn Tinsley
    Department of Molecular Genetics and Biochemistry, University of Pittsburgh School of Medicine, East 1240 Biomedical Science Tower, Pittsburgh, PA 15261
    J Bacteriol 188:2829-35. 2006

Collaborators

Detail Information

Publications24

  1. ncbi request reprint Plasmid rolling-circle replication: recent developments
    S A Khan
    Department of Molecular Genetics and Biochemistry, University of Pittsburgh School of Medicine, Pittsburgh, PA 15261, USA
    Mol Microbiol 37:477-84. 2000
    ....
  2. pmc Alteration of microRNA profiles in squamous cell carcinoma of the head and neck cell lines by human papillomavirus
    Abigail I Wald
    Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
    Head Neck 33:504-12. 2011
    ..Differences in microRNA (miRNA) expression may affect their clinical outcomes...
  3. ncbi request reprint Plasmid rolling-circle replication: highlights of two decades of research
    Saleem A Khan
    Department of Molecular Genetics and Biochemistry, University of Pittsburgh School of Medicine, Pittsburgh, PA 15261, USA
    Plasmid 53:126-36. 2005
    ..This minireview will highlight the major findings in the study of plasmid RC replication over the past twenty years. Regulation of replication of RCR plasmids will not be included since it is the subject of another review...
  4. doi request reprint Marked increase in biofilm-derived rough pneumococcal variants and rifampin-resistant strains not due to hex gene mutations
    M Catherine McEllistrem
    University of Pittsburgh, Department of Medicine, Pittsburgh, Pennsylvania, USA
    Microb Drug Resist 15:85-90. 2009
    ..Taken together, these data suggest that mutations in the hex genes and modulation of hexA activity are unlikely to account for the generation of biofilm-derived rough variants...
  5. pmc DNA helicase activity of PcrA is not required for the displacement of RecA protein from DNA or inhibition of RecA-mediated strand exchange
    Syam P Anand
    Department of Molecular Genetics and Biochemistry, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania 15261, USA
    J Bacteriol 189:4502-9. 2007
    ..Further, our results show that the helicase activity of PcrA, although not essential, might play a facilitatory role in the RecA displacement reaction...
  6. ncbi request reprint Biochemical characterization of the Staphylococcus aureus PcrA helicase and its role in plasmid rolling circle replication
    Tseh Ling Chang
    Department of Molecular Genetics and Biochemistry, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania 15261, USA
    J Biol Chem 277:45880-6. 2002
    ....
  7. ncbi request reprint Detection of very high-level penicillin-resistant variants of the Tennessee (23 F)-4 clone via single and serial transformations with four serotype 19 A international pneumococcal clones
    M Catherine McEllistrem
    University of Pittsburgh School of Medicine, Pittsburgh, PA 15213 2582, USA
    Microb Drug Resist 11:271-8. 2005
    ..Recombination within the MLST housekeeping genes was commonly detected in the transformants that had acquired penicillin resistance...
  8. pmc Expedient placement of two fluorescent dyes for investigating dynamic DNA protein interactions in real time
    Sanford H Leuba
    Department of Cell Biology, University of Pittsburgh School of Medicine and Swanson School of Engineering, Petersen Institute of NanoScience and Engineering and University of Pittsburgh Cancer Institute, Pittsburgh, PA, 15213, USA
    Chromosome Res 16:451-67. 2008
    ..Thus, appropriately placed fluorescent dyes can be used to monitor conformational changes occurring in DNA and or proteins and provide increased sensitivity for investigating dynamic DNA-protein interactions in real time...
  9. pmc Characterization of in vitro biofilm-associated pneumococcal phase variants of a clinically relevant serotype 3 clone
    M Catherine McEllistrem
    Division of Infectious Diseases, University of Pittsburgh School of Medicine, PA 15213 2582, USA
    J Clin Microbiol 45:97-101. 2007
    ..These in vitro phase variation data, which underscore the plasticity of the pneumococcus, need to be confirmed with in vivo analyses of the middle ear mucosa during otitis media...
  10. pmc A novel FtsZ-like protein is involved in replication of the anthrax toxin-encoding pXO1 plasmid in Bacillus anthracis
    Eowyn Tinsley
    Department of Molecular Genetics and Biochemistry, University of Pittsburgh School of Medicine, East 1240 Biomedical Science Tower, Pittsburgh, PA 15261
    J Bacteriol 188:2829-35. 2006
    ..anthracis and possibly in related organisms. Such replication proteins may provide novel drug targets for the elimination of plasmids encoding the anthrax toxin and other virulence factors...
  11. pmc Bacillus anthracis and Bacillus cereus PcrA helicases can support DNA unwinding and in vitro rolling-circle replication of plasmid pT181 of Staphylococcus aureus
    Syam P Anand
    Department of Molecular Genetics and Biochemistry, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania 15261, USA
    J Bacteriol 186:2195-9. 2004
    ..The ability of PcrA helicases to unwind noncognate RCR plasmids may contribute to the broad-host-range replication and dissemination of RCR plasmids in gram-positive bacteria...
  12. ncbi request reprint Human papillomavirus-16 associated squamous cell carcinoma of the head and neck (SCCHN): a natural disease model provides insights into viral carcinogenesis
    Robert L Ferris
    UPCI Research Pavilion, The Hillman Cancer Center, 5117 Centre Avenue, Room 1 19d, Pittsburgh, PA 15213 1863, USA
    Eur J Cancer 41:807-15. 2005
    ..The results of our studies are consistent with a causative role of HPV-16 in the pathogenesis of SCCHN...
  13. ncbi request reprint The PcrA3 mutant binds DNA and interacts with the RepC initiator protein of plasmid pT181 but is defective in its DNA helicase and unwinding activities
    Syam P Anand
    Department of Molecular Genetics and Biochemistry, University of Pittsburgh School of Medicine, Pittsburgh, PA 15261, USA
    Plasmid 54:104-13. 2005
    ..Rather, it is likely that a defect in its helicase activity is responsible for its inability to replicate the pT181 plasmid...
  14. pmc Structure-specific DNA binding and bipolar helicase activities of PcrA
    Syam P Anand
    Department of Molecular Genetics and Biochemistry, University of Pittsburgh School of Medicine, 200 Lothrop Street, Pittsburgh, PA 15261, USA
    Nucleic Acids Res 32:3190-7. 2004
    ..Our data indicate that PcrA may recognize DNA substrates with specific structures in vivo and its 5'-->3' and 3'-->5' helicase activities may be involved in distinct cellular processes...
  15. pmc Isolation of a minireplicon of the virulence plasmid pXO2 of Bacillus anthracis and characterization of the plasmid-encoded RepS replication protein
    Eowyn Tinsley
    Department of Molecular Genetics and Biochemistry, University of Pittsburgh School of Medicine, East 1240 Biomedical Science Tower, Pittsburgh, PA 15261, USA
    J Bacteriol 186:2717-23. 2004
    ..Competition DNA binding experiments showed that the 5' and central regions of the putative origin were important for RepS binding. MBP-RepS also bound nonspecifically to single-stranded DNA with a lower affinity...
  16. pmc A Bacillus anthracis-based in vitro system supports replication of plasmid pXO2 as well as rolling-circle-replicating plasmids
    Eowyn Tinsley
    Department of Molecular Genetics and Biochemistry, University of Pittsburgh School of Medicine, East 1240 Biomedical Science Tower, Pittsburgh, PA 15261, USA
    Appl Environ Microbiol 73:5005-10. 2007
    ..anthracis. Replication of pXO2 required directional transcription through the plasmid origin of replication, and increased transcription through the origin resulted in an increase in plasmid replication...
  17. pmc The tubulin-like RepX protein encoded by the pXO1 plasmid forms polymers in vivo in Bacillus anthracis
    Parvez Akhtar
    Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine, East 1240 Biomedical Science Tower, Pittsburgh, PA 15261, USA
    J Bacteriol 191:2493-500. 2009
    ..We discuss the significance of our observations in view of the plasmid-specific functions that have been proposed for RepX and related proteins encoded by several megaplasmids found in members of the Bacillus cereus group of bacteria...
  18. doi request reprint GTP-dependent polymerization of the tubulin-like RepX replication protein encoded by the pXO1 plasmid of Bacillus anthracis
    Syam P Anand
    Department of Microbiology and Molecular Genetics, School of Medicine, University of Pittsburgh, Pittsburgh, PA, USA
    Mol Microbiol 67:881-90. 2008
    ..We speculate that RepX may be involved in both the replication and segregation of the pXO1 plasmid...
  19. ncbi request reprint DNA-protein interactions during the initiation and termination of plasmid pT181 rolling-circle replication
    Saleem A Khan
    Department of Molecular Genetics and Biochemistry, University of Pittsburgh School of Medicine, Pittsburgh, PA 15261, USA
    Prog Nucleic Acid Res Mol Biol 75:113-37. 2003
    ..Finally, the review will outline the mechanism of replication of the lagging strand of the pT181 plasmid as well as the limited information that is available on the role of host proteins in pT181 leading- and lagging-strand replication...
  20. ncbi request reprint Identification of a 450-bp region of human papillomavirus type 1 that promotes episomal replication in Saccharomyces cerevisiae
    Anasuya Chattopadhyay
    Department of Molecular Genetics and Biochemistry, University of Pittsburgh School of Medicine, Room East 1240 Biomedical Science Tower, Pittsburgh, PA 15261, USA
    Virology 340:133-42. 2005
    ..The HPV-1 ARS does not include the binding sites for the viral E1 and E2 proteins, and these proteins are dispensable for replication in S. cerevisiae...
  21. ncbi request reprint Purification and biochemical characterization of the E1 replication initiation protein of the cutaneous human papillomavirus type 1
    Saifuddin Sheikh
    Department of Molecular Genetics and Biochemistry, University of Pittsburgh School of Medicine, PA 15261, USA
    J Gen Virol 84:277-85. 2003
    ..Our results suggest that the ability of the HPV-1 E1 protein to initiate DNA replication in vivo in the absence of the E2 protein may be due to its stable interaction with the HPV-1 origin...
  22. pmc Purification and characterization of the PcrA helicase of Bacillus anthracis
    Asma Naqvi
    Department of Molecular Genetics and Biochemistry, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania 15261, USA
    J Bacteriol 185:6633-9. 2003
    ..Our results suggest that specialized DNA structures and/or sequences represent natural substrates of PcrA in biochemical processes that are essential for the growth and survival of gram-positive organisms, including B. anthracis...
  23. pmc Identification of differentially expressed genes in HPV-positive and HPV-negative oropharyngeal squamous cell carcinomas
    Ivan Martinez
    Department of Molecular Genetics and Biochemistry, University of Pittsburgh School of Medicine, Room East 1240, 200 Lothrop Street, Pittsburgh, PA 15208, USA
    Eur J Cancer 43:415-32. 2007
    ..Our results reveal specific gene expression patterns in HPV-positive and HPV-negative oropharyngeal squamous carcinomas that may serve as potential biomarkers for the development of SCCHN...
  24. pmc Dicer-regulated microRNAs 222 and 339 promote resistance of cancer cells to cytotoxic T-lymphocytes by down-regulation of ICAM-1
    Ryo Ueda
    Department of Neurological Surgery, University of Pittsburgh School of Medicine, Pittsburgh, PA 15213, USA
    Proc Natl Acad Sci U S A 106:10746-51. 2009
    ..This study suggests development of novel miR-targeted therapy to promote cytolysis of tumor cells...

Research Grants35

  1. Plasmid Biology 2002 Symposium
    Saleem Khan; Fiscal Year: 2002
    ..NIH funds are requested to partly defray such costs as organization expenses, brochure and abstract book preparation, travel expenses and boarding and lodging expenses of several participants. ..
  2. PLASMID PT181 DNA REPLICATION IN STAPHYLOCOCCUS AUREUS
    Saleem Khan; Fiscal Year: 2003
    ..These studies are expected to provide information on the replication and maintenance of drug resistance plasmids in S. aureus and other Gram-positive bacteria that replicate by an RC mechanism. ..
  3. Plasmid pXO2 Replication in Bacillus anthracis
    Saleem Khan; Fiscal Year: 2005
    ..anthracis and use these to study pXO2 replication in vitro. Our studies may reveal new molecular targets for therapeutics that affect plasmid replication and/or maintenance during infection. ..
  4. Genomics/Proteomics of Enterotoxin B Producing S. aureus
    Saleem Khan; Fiscal Year: 2005
    ..abstract_text> ..
  5. PerA Helicase and Replication of Drug Resistance Plasmid
    Saleem Khan; Fiscal Year: 2004
    ..These studies may facilitate the development of antimicrobial drugs targeting the PcrA helicase and/or the initiators of RCR plasmids. ..
  6. Genomic and Proteomic Analysis of HPV-Associated SCCHN
    Saleem Khan; Fiscal Year: 2007
    ..Our studies will provide important information on cellular pathways altered during tumor progression in both HPV-positive and HPV-negative SCCHN. ..
  7. Functions of the PcrA Helicase in Bacillus anthracis
    Saleem Khan; Fiscal Year: 2007
    ..anthracis. Future development of drugs that specifically inhibit the functions of the PcrA helicase could add to the treatment regimen against B. anthracis and related organisms. ..
  8. Plasmid pT181 Replication and PcrA Helicase of S. aureus
    Saleem Khan; Fiscal Year: 2007
    ..Our studies could provide new avenues for the development of novel drugs targeting RCR plasmids, as well as targeting an essential helicase in S. aureus and other Gram-positive bacteria. ..
  9. Genomic and Proteomic Analysis of HPV-Associated SCCHN
    Saleem Khan; Fiscal Year: 2009
    ..Our studies will provide important information on cellular pathways altered during tumor progression in both HPV-positive and HPV-negative SCCHN. ..
  10. PLASMID PT181 DNA REPLICATION IN STAPHYLOCOCCUS AUREUS
    Saleem Khan; Fiscal Year: 2000
    ..A model for the roles of the two RepC monomers in replication and its regulation will be developed. (iv) Finally, crystallization studies of RepC are proposed. ..
  11. PLASMID PT181 DNA REPLICATION IN STAPHYLOCOCCUS AUREUS
    Saleem Khan; Fiscal Year: 1993
    ....
  12. Plasmid pT181 Replication and PcrA Helicase of S. aureus
    Saleem Khan; Fiscal Year: 2009
    ..Our studies could provide new avenues for the development of novel drugs targeting RCR plasmids, as well as targeting an essential helicase in S. aureus and other Gram-positive bacteria. ..