A conserved polar region in the cell division site determinant MinD is required for responding to MinE-induced oscillation but not for localization within coiled arrays.
A region in the cell division site determinant MinD required for stimulation by MinE and which determines MinD topological specificity along coil-like structures has been identified. Structural modeling of dimeric MinD and sequence alignment of 24 MinD proteins revealed a conserved polar region in Gram-negative bacterial MinD proteins, corresponding to residues 92-94 of Neisseria gonorrhoeae MinD (MinD(Ng)). Using MinD(Ng) as a paradigm for MinD functionality in Gram-negative organisms, mutation of these conserved residues did not abrogate MinD(Ng) self-association, nor its interaction with MinE(Ng) and the cell division inhibitor MinC. Although the MinD(Ng) mutant dimerized in the presence of ATP, its ATPase activity was not stimulated by MinE(Ng), unlike wild-type MinD(Ng). GFP fusions to either MinD(Ng) or to Escherichia coli MinD bearing simultaneous or individual mutations to residues 92-94 localized within coiled arrays along the E. coli inner cell periphery, similar to wild-type GFP-MinD. However, unlike wild-type GFP-fusions, the mutant proteins were distributed uniformly throughout the array, despite the presence of MinE, which normally imparts topological specificity to MinD by inducing the latter to oscillate from pole-to-pole and away from midcell. Hence, despite localizing along the inner cell periphery as a polymeric structure, the mutant MinD proteins in this study have lost the ability to be efficiently stimulated by MinE(Ng), resulting in a loss of distinct pole-to-pole oscillation.
Szeto
Jason
J
Department of Biochemistry, Microbiology, and Immunology, University of Ottawa, 451 Smyth Road, Ottawa, Ontario, K1H 8M5, Canada.
Eng
Nelson F
NF
Acharya
Sudeep
S
Rigden
Marc D
MD
Dillon
Jo-Anne R
JA
D000251:Adenosine Triphosphatases / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D000255:Adenosine Triphosphate / Q000378:metabolism; D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D017124:Conserved Sequence; D003593:Cytoplasm / Q000737:chemistry; D019281:Dimerization; D029968:Escherichia coli Proteins / Q000235:genetics / Q000378:metabolism; D017930:Genes, Reporter; D049452:Green Fluorescent Proteins / Q000032:analysis / Q000235:genetics; D008958:Models, Molecular; D008969:Molecular Sequence Data; D009154:Mutation; D009344:Neisseria gonorrhoeae / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*; D011485:Protein Binding; D011487:Protein Conformation; D017434:Protein Structure, Tertiary; D011993:Recombinant Fusion Proteins / Q000032:analysis; D017386:Sequence Homology, Amino Acid
D001426:Bacterial Proteins; D029968:Escherichia coli Proteins; C080466:MinC protein, Bacteria; D011993:Recombinant Fusion Proteins; D049452:Green Fluorescent Proteins; D000255:Adenosine Triphosphate; D000251:Adenosine Triphosphatases; C072069:MinD protein, E coli; C439050:MinD protein, Neisseria gonorrhoeae