Conditional lethal mutations separate the M13 procoat and Pf3 coat functions of YidC: different YIDC structural requirements for membrane protein insertion.
Conditional lethal YidC mutants have been isolated to decipher the role of YidC in the assembly of Sec-dependent and Sec-independent membrane proteins. We now show that the membrane insertion of the Sec-independent M13 procoat-lep protein is inhibited in a short time in a temperature-sensitive mutant when shifted to the nonpermissive temperature. This provides an additional line of evidence that YidC plays a direct role in the insertion of the Sec-independent M13 procoat protein. However, in the temperature-sensitive mutant, the insertion of the Sec-independent Pf3 phage coat protein and the Sec-dependent leader peptidase were not strongly inhibited at the restricted temperatures. Conversely, using a cold-sensitive YidC strain, we find that the membrane insertion of the Sec-independent Pf3 coat protein is blocked, and the Sec-dependent leader peptidase is inhibited at the nonpermissive temperature, whereas the insertion of the M13 procoat protein is nearly normal. These data show that the YidC function for procoat and its function for Pf3 coat and possibly leader peptidase are genetically separable and suggest that the YidC structural requirements are different for the Sec-independent M13 procoat and Pf3 coat phage proteins that insert by different mechanisms.
Chen
Minyong
M
Department of Chemistry and Biochemistry Program, The Ohio State University, Columbus, Ohio 43210, USA.
Xie
Kun
K
Nouwen
Nico
N
Driessen
Arnold J M
AJ
Dalbey
Ross E
RE
D000251:Adenosine Triphosphatases / Q000502:physiology; D001426:Bacterial Proteins; D017104:Bacteriophage M13 / Q000737:chemistry / Q000502:physiology; D002213:Capsid / Q000378:metabolism* / Q000502:physiology; D036022:Capsid Proteins; D004926:Escherichia coli / Q000821:virology*; D029968:Escherichia coli Proteins / Q000235:genetics / Q000502:physiology*; D005804:Genes, Lethal / Q000502:physiology*; D008565:Membrane Proteins; D026901:Membrane Transport Proteins / Q000235:genetics / Q000502:physiology*; D009154:Mutation; D011498:Protein Precursors / Q000378:metabolism* / Q000502:physiology; D021382:Protein Sorting Signals; D021381:Protein Transport; D000069816:SEC Translocation Channels; D000081416:SecA Proteins; D012697:Serine Endopeptidases; D013696:Temperature
D001426:Bacterial Proteins; D036022:Capsid Proteins; D029968:Escherichia coli Proteins; D008565:Membrane Proteins; D026901:Membrane Transport Proteins; D011498:Protein Precursors; D021382:Protein Sorting Signals; D000069816:SEC Translocation Channels; C412443:YIDC protein, E coli; C025668:coat protein, Bacteriophage M13; C084332:major coat protein, Pseudomonas phage Pf3; D012697:Serine Endopeptidases; C026515:type I signal peptidase; D000251:Adenosine Triphosphatases; D000081416:SecA Proteins