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Identification and characterization of the biochemical function of A grobacterium T ‐complex‐recruiting protein A tu5117
Author(s) -
Gao Diankun,
Bian Xiaowei,
Guo Minliang,
Wang Jing,
Zhang Xin
Publication year - 2013
Publication title -
the febs journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.981
H-Index - 204
eISSN - 1742-4658
pISSN - 1742-464X
DOI - 10.1111/febs.12460
Subject(s) - cytosol , nucleotide , agrobacterium tumefaciens , biochemistry , function (biology) , atpase , chemistry , enzyme , biology , microbiology and biotechnology , gene , transgene
Atu5117 from A grobacterium tumefaciens is a highly conserved protein with a putative nucleotidyltransferase domain in its N ‐terminal region and a putative higher eukaryotes and prokaryotes nucleotide‐binding domain in its C ‐terminal region. This protein has been shown to be a T ‐complex‐recruiting protein that can recruit T ‐complex from the cytosol to the polar VirB/D4 type IV secretion system (T4SS). However, the biochemical function of Atu5117 is still unknown. Here, we show that Atu5117 is a (d)NTPase. Although no proteins with nucleotidyltransferase and higher eukaryotes and prokaryotes nucleotide‐binding domains were identified as (d)NTPases, Atu5117 was able to convert all eight canonical NTP s and d NTP s to NDP , d NDP and inorganic phosphate in vitro , and required Mg 2+ for its (d) NTP ase activity. The kinetic parameters of Atu5117 (d) NTP ase for eight substrates were characterized. Kinetic data showed that Atu5117 (d) NTP ase preferred ATP as its substrate. The optimal conditions for (d) NTP ase activity of Atu5117 were very similar to those required for A grobacterium tumorigenesis. The kinetic parameters of (d) NTP ase of Atu5117 for all four canonical NTP s were in the same orders of magnitude as the kinetic parameters of the ATP ases identified in some components of the VirB/D4 T4SS. These results suggest that Atu5117 might function as an energizer to recruit T ‐complex to the T4SS transport site.