Analysis of HI0220 Protein from Haemophilus influenzae, a Novel Structural and Functional Analog of ArcB Protein from Escherichia coli

I. V. Manukhov^1,2, Yu. V. Bertsova¹, D. Yu. Trofimov³, A. V. Bogachev¹, and V. P. Skulachev^1*

¹Department of Bioenergetics, Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow, 119899 Russia; fax: (095) 939-0338; E-mail: skulach@head.genebee.msu.su

²State Scientific Center of the Russian Federation GNIIGENETIKA, Moscow, Russia; fax: (095) 315-0501; E-mail: manukhov@yahoo.com

³Institute of Immunology, Moscow, 115478 Russia; fax: (095) 117-7822; E-mail: dna-tech@portal.ru

^* To whom correspondence should be addressed.

Received June 2, 2000; Revision received August 14, 2000

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A Haemophilus influenzae gene encoding a protein with high homology to ArcB receptor protein from Escherichia coli has been cloned. An error in the previously reported sequence of this gene has been found, thus increasing its open reading frame. The cloned gene comprising the entire open reading frame restores oxygen-dependent regulation of succinate dehydrogenase in an ArcB-deficient E. coli strain. Thus, this gene is a functional analog of ArcB from E. coli. By screening partially sequenced bacterial genomes using the BLAST program, proteins with high homology to ArcB protein from E. coli were found in Salmonella typhi, Yersinia pestis, Vibrio cholerae, and Pasteurella multocida. Comparison of these proteins with ArcB protein from E. coli and H. influenzae revealed conserved amino acid regions. Transmembrane helix II was shown to be highly homologous in all the ArcB-type proteins. The involvement of this region in ArcB-mediated oxygen-dependent regulation is suggested.

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KEY WORDS: ArcB, expression regulation, PAS domain, Escherichia coli, Haemophilus influenzae

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