PubMed Health⌕ Search

Biomedical subjects

J L Voskuil

Publications and source records attributed to J L Voskuil.

2 recordsLinked to original sources
PubMed1996

How does FtsZ find its location?

The conformational flexibility of FtsZ and the properties of its epitopes have been studied. Cellular fractions of Escherichia coli have been treated with Triton X-114. FtsZ distributed in the polar as well as in the non-polar phase. This has been interpreted to mean that FtsZ can change its conformation. For the nonpolar conformation it has been assumed that the putative hydrophobic pocket of FtsZ (cf. Voskuil et al., J. Bacteriol. 176:1886-1893) is being turned inside out upon interaction with the cytoplasmic membrane. In a tentative model we suggest that FtsA mediates this interaction. Immunoprecipitations of FtsZ with various monoclonal antibodies in the presence or absence of 1 M NaCl gave a clue concerning the hydrophobicity and hydrophilicity of FtsZ's epitopes. Immunogold-labeling also showed differences with respect to the accessibility of FtsZ.

Antibodies, Monoclonal↗
PubMed1994

Epitope mapping of Escherichia coli cell division protein FtsZ with monoclonal antibodies.

A fusion between lacZ and ftsZ of Escherichia coli was constructed to obtain a beta-galactosidase-FtsZ fusion protein. This fusion protein was used to raise antibodies against cell division protein FtsZ. Six monoclonal antibodies were obtained, and they reacted with FtsZ from cytoplasm and membrane fractions. The epitopes in FtsZ were localized by studying the reactions of the monoclonal antibodies with fusion proteins truncated at the carboxy terminus and with fragments that were obtained by CNBr cleavage of purified FtsZ. Five different epitopes were defined. Epitopes I and III reacted with the same monoclonal antibody, without showing apparent amino acid homology. Epitope II was defined by monoclonal antibodies that cross-reacted with an unknown cytoplasmic 50-kDa protein not related to FtsZ. Epitopes IV and V were recognized by different monoclonal antibodies. All monoclonal antibodies reacted strongly under native conditions, so it is likely that the five epitopes are situated on the surface of native FtsZ. By using these data and computer analysis, a provisional model of FtsZ is proposed. The FtsZ protein is considered to be globular, with a hydrophobic pocket containing GTP-binding elements. Epitopes I and II are situated on each side of the hydrophobic pocket. Because the carboxy terminus contains epitope V, the carboxy terminus of FtsZ is likely oriented toward the protein's surface.

Animals↗