Random sequence analysis of genomic DNA of a hyperthermophile: Aquifex pyrophilus

In Geol Choi, Sang Suk Kim, Jae Ryeon Ryu, Ye Sun Han, Won Gi Bang, Sung Hou Kim, Yeon Gyu Yu

Research output: Contribution to journalArticlepeer-review

12 Citations (Scopus)


Aquifex pyrophilus is one of the hyperthermophilic bacteria that can grow at temperatures up to 95°C. To obtain information about its genomic structure, random sequencing was performed on plasmid libraries containing 0.5-2 kb genomic DNA fragments of A. pyrophilus. Comparison of the obtained sequence tags with known proteins revealed that 123 tags showed strong similarity to previously identified proteins in the PIR or Genebank databases. These included three proteases, two amino acid racemases, and three enzymes utilizing oxygen as substrate. Although the GC ratio of the genome is about 40%, the codon usage of A. pyrophilus showed biased occurrence of G and C at the third position of codons, especially those for amino acids such as asparagine, aspartic acid, cysteine, glutamine, glutamic acid, histidine, lysine, and tyrosine. A higher ratio of positively charged amino acids in A. pyrophilus proteins as compared with proteins from mesophiles suggested that Aquifex proteins might contain increased ion-pair interaction that could help to maintain heat stability.

Original languageEnglish
Pages (from-to)125-134
Number of pages10
Issue number3
Publication statusPublished - 1997
Externally publishedYes

Bibliographical note

Funding Information:
Acknowledgments We thank Dr. K.-S. Kim of the Structural Biology Center of the Korea Institute of Science and Technology for helpful advice on the application of the SEQSEE and BLAST programs. This work is supported by a grant from the Ministry of Science and Technology, Korea. The work of S.-H. Kim has been supported by the Office of Health and Environmental Research, U.S. Department of Energy (DE-AC03-765F00098).


  • Aquifex pyrophilus
  • Hyperthermophile Genome sequence
  • Oxidase
  • Protease
  • Racemase

ASJC Scopus subject areas

  • Microbiology
  • Molecular Medicine


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