Related Experiment Video
Updated: Aug 16, 2026
Generation of Null Mutants to Elucidate the Role of Bacterial Glycosyltransferases in Bacterial Motility
Published on: March 11, 2022
Mutant analysis reveals a specific requirement for protein P30 in Mycoplasma pneumoniae gliding motility
Benjamin M Hasselbring1, Jarrat L Jordan, Duncan C Krause
1Department of Microbiology, University of Georgia, 523 Biological Sciences Building, Athens, Georgia 30602, USA.
Abstract:
The cell-wall-less prokaryote Mycoplasma pneumoniae, long considered among the smallest and simplest cells capable of self-replication, has a distinct cellular polarity characterized by the presence of a differentiated terminal organelle which functions in adherence to human respiratory epithelium, gliding motility, and cell division. Characterization of hemadsorption (HA)-negative mutants has resulted in identification of several terminal organelle proteins, including P30, the loss of which results in developmental defects and decreased adherence to host cells, but their impact on M. pneumoniae gliding has not been investigated. Here we examined the contribution of P30 to gliding motility on the basis of satellite growth and cell gliding velocity and frequency. M. pneumoniae HA mutant II-3 lacking P30 was nonmotile, but HA mutant II-7 producing a truncated P30 was motile, albeit at a velocity 50-fold less than that of the wild type. HA-positive revertant II-3R producing an altered P30 was unexpectedly not fully wild type with respect to gliding. Complementation of mutant II-3 with recombinant wild-type and mutant alleles confirmed the correlation between gliding defect and loss or alteration in P30. Surprisingly, fusion of yellow fluorescent protein to the C terminus of P30 had little impact on cell gliding velocity and significantly enhanced HA. Finally, while quantitative examination of HA revealed clear distinctions among these mutant strains, gliding defects did not correlate strictly with the HA phenotype, and all strains attached to glass at wild-type levels. Taken together, these findings suggest a role for P30 in gliding motility that is distinct from its requirement in adherence.
Insights
The protein P30 is crucial for Mycoplasma pneumoniae gliding motility, distinct from its role in adherence. Loss or alteration of P30 significantly impairs M. pneumoniae cell movement.
Area of Science:
- Microbiology
- Cell Biology
- Prokaryotic Cell Structure and Function
Background:
- Mycoplasma pneumoniae, a wall-less prokaryote, possesses a terminal organelle essential for adherence, motility, and division.
- The protein P30 is a component of this organelle, and its absence causes developmental defects and reduced adherence.
- The specific role of P30 in M. pneumoniae gliding motility has not been previously investigated.
Purpose of the Study:
- To investigate the contribution of the P30 protein to the gliding motility of Mycoplasma pneumoniae.
- To determine if P30's role in gliding is separate from its known function in hemadsorption (adherence).
Main Methods:
- Analysis of hemadsorption (HA)-negative M. pneumoniae mutants lacking or having altered P30.
- Assessment of gliding motility through satellite growth, gliding velocity, and frequency measurements.
- Complementation studies using recombinant wild-type and mutant P30 alleles.
- Quantitative examination of hemadsorption and cell attachment to glass.
Main Results:
- M. pneumoniae lacking P30 was nonmotile, while a strain with truncated P30 showed significantly reduced gliding velocity (50-fold less than wild type).
- Altered P30 in a revertant strain also resulted in impaired gliding, confirming P30's correlation with motility.
- Fusion of yellow fluorescent protein to P30 minimally affected gliding velocity but enhanced hemadsorption.
- Gliding defects did not strictly correlate with hemadsorption phenotypes, and all strains showed wild-type attachment to glass.
Conclusions:
- P30 plays a significant role in Mycoplasma pneumoniae gliding motility.
- The function of P30 in gliding motility is distinct and separable from its role in adherence.
- P30's structural integrity is important for efficient gliding, but alterations do not abolish adherence.
