Mycobacterium tuberculosis FtsZ requires at least one arginine residue at the C-terminal end for polymerization in vitro.
We examined whether C-terminal residues of soluble recombinant FtsZ of Mycobacterium tuberculosis (MtFtsZ) have any role in MtFtsZ polymerization in vitro. MtFtsZ-deltaC1, which lacks C-terminal extreme Arg residue (underlined in the C-terminal extreme stretch of 13 residues, DDDDVDVPPFMRR), but retaining the penultimate Arg residue (DDDDVDVPPFMR), polymerizes like full-length MtFtsZ in vitro. However, MtFtsZ-deltaC2 that lacks both the Arg residues at the C-terminus (DDDDVDVPPFM), neither polymerizes at pH 6.5 nor forms even single- or double-stranded filaments at pH 7.7 in the presence of 10 mM CaCl(2). Neither replacement of the penultimate Arg residue, in the C-terminal Arg deletion mutant DDDDVDVPPFMR, with Lys or His or Ala or Asp (DDDDVDVPPFMK/H/A/D) enabled polymerization. Although MtFtsZ-deltaC2 showed secondary and tertiary structural changes, which might have affected polymerization, GTPase activity of MtFtsZ-deltaC2 was comparable to that of MtFtsZ. These data suggest that MtFtsZ requires an Arg residue as the extreme C-terminal residue for polymerization in vitro. The polypeptide segment containing C-terminal 67 residues, whose coordinates were absent from MtFtsZ crystal structure, was modeled on tubulin and MtFtsZ dimers. Possibilities for the influence of the C-terminal Arg residues on the stability of the dimer and thereby on MtFtsZ polymerization have been discussed.
Gupta
Prabuddha
P
Department of Microbiology and Cell Biology, Indian Institute of Science, Bangalore, India.
Rajeswari
Haryadi
H
Arumugam
Muthu
M
Mishra
Saurabh
S
Bhagavat
Raghu
R
Anand
Praveen
P
Chandra
Nagasuma
N
Srinivasan
Ramanujam
R
Indi
Shantinath
S
Ajitkumar
Parthasarathi
P
D000429:Alcohol Oxidoreductases / Q000378:metabolism*; D000595:Amino Acid Sequence / Q000235:genetics; D001120:Arginine / Q000737:chemistry / Q000378:metabolism*; D001224:Aspartic Acid / Q000378:metabolism*; D001426:Bacterial Proteins / Q000737:chemistry / Q000378:metabolism*; D003001:Cloning, Molecular; D003598:Cytoskeletal Proteins / Q000737:chemistry / Q000378:metabolism*; D004268:DNA-Binding Proteins / Q000378:metabolism*; D015964:Gene Expression Regulation, Bacterial; D026901:Membrane Transport Proteins / Q000378:metabolism; D008969:Molecular Sequence Data; D009169:Mycobacterium tuberculosis / Q000737:chemistry*; D013379:Substrate Specificity
D001426:Bacterial Proteins; D003598:Cytoskeletal Proteins; D004268:DNA-Binding Proteins; C071525:FtsZ protein, Bacteria; D026901:Membrane Transport Proteins; D001224:Aspartic Acid; D001120:Arginine; D000429:Alcohol Oxidoreductases; C096794:C-terminal binding protein