TAILIEUCHUNG - Báo cáo khoa học: Tamavidins – novel avidin-like biotin-binding proteins from the Tamogitake mushroom

Mycobacterium tuberculosis glutamyl–tRNA synthetase (Mt-GluRS), encoded by Rv2992c, was overproduced inEscherichia colicells, and puri-fied to homogeneity. It was found to be similar to the other well-character-ized GluRS, especially the E. colienzyme, with respect to the requirement for bound tRNA Glu to produce the glutamyl-AMP intermediate, and the steady-state kinetic parameterskcat (130 min )1 ) and KMfor tRNA ( lm) and ATP (78lm), but to differ by a one order of magnitude higher KM value forl-Glu ( mm). . | Tamavidins - novel avidin-like biotin-binding proteins from the Tamogitake mushroom Yoshimitsu Takakura1 Masako Tsunashima1 Junko Suzuki1 Satoru Usami1 Yoshimitsu Kakuta2 Nozomu Okino2 Makoto Ito2 and Takeshi Yamamoto1 1 Plant Innovation Center Japan Tobacco Inc. Shizuoka Japan 2 Department of Bioscience and Biotechnology Graduate Schoolof Bioresource and BioenvironmentalSciences Kyushu University Fukuoka Japan Keywords avidin biotin binding crystal structure Escherichia coli interaction Correspondence Y. Takakura Plant Innovation Center Japan Tobacco Inc. 700 Higashibara Iwata Shizuoka 438-0802 Japan Fax 81 538 33 6046 Tel 81 538 32 8291 E-mail Received 24 November 2008 revised 22 December 2008 accepted 24 December 2008 doi Novel biotin-binding proteins referred to herein as tamavidin 1 and tamavidin 2 were found in a basidiomycete fungus Pleurotus cornucopiae known as the Tamogitake mushroom. These are the first avidin-like proteins to be discovered in organisms other than birds and bacteria. Tam-avidin 1 and tamavidin 2 have amino acid sequences with 31 and 36 identity respectively to avidin and 47 and 48 identity respectively to streptavidin. Unlike any other biotin-binding proteins tamavidin 1 and tamavidin 2 are expressed as soluble proteins at a high level in Escherichia coli. Recombinant tamavidin 2 was purified as a tetrameric protein in a single step by 2-iminobiotin affinity chromatography with a yield of 5 mg per 100 mL culture of E. coli. The kinetic parameters measured by a BIA-core biosensor indicated that recombinant tamavidin 2 binds biotin with high affinity in a similar manner to binding by avidin and streptavidin. The overall crystal structure of recombinant tamavidin 2 is similar to that of avidin and streptavidin. However recombinant tamavidin 2 is immunologically distinct from avidin and streptavidin. Tamavidin 2 and streptavidin are very similar in terms of the arrangement of

• Báo cáo khoa học
• medical reports
• thesis report
• traditional medicine
• medical knowledge
• cytoplasm
• analysis of cytoplasmic
• statements and documents scientific reports
• medical research
• clinical trials
• medical management
• health care
• medical transfer
• the developing countries