Expression and Properties of Bacteriophage T4 Gene Product 11

L. P. Kurochkina^1,2*, P. G. Leiman^1,2, S. Yu. Venyaminov³, and V. V. Mesyanzhinov¹

¹Shemyakin and Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, ul. Miklukho-Maklaya 16/10, Moscow, 117871 Russia; fax: (095) 336-6022; E-mail: vvm@ibch.siobc.ras.ru

²Bach Institute of Biochemistry, Russian Academy of Sciences, Leninskii pr. 33, Moscow, 117071 Russia

³Department of Biochemistry and Molecular Biology, Mayo Foundation, 200 First Street SW, Rochester, Minnesota, 55905, USA

^* To whom correspondence should be addressed.

Received September 13, 2000; Revision received November 5, 2000

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A plasmid vector for expression of bacteriophage T4 gene product 11 (gp11) in E. coli cells has been constructed. Gp11 is a baseplate protein that connects short tail fibers providing irreversible adsorption of the virus on a cell. A method based on chromatography on hydroxyapatite has been developed for purification of recombinant gp11. The protein is active in an in vitro complementation assayand transforms defective phage particles lacking gp11 into infective ones. Gel filtration data suggest that the biologically active protein is a trimer. According to CD spectroscopy and sequence analysis data, the polypeptide chain of gp11 contains not less than 20% alpha-helical segments, about 30% beta-structure, and belongs to the class of alpha/beta structural proteins.

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KEY WORDS: bacteriophage T4, baseplate, gene product 11, protein folding

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