Table 3.

Spatial distribution of chemoreceptors in cells expressing different CheA variantsa

StrainChromosome-encoded CheAPlasmid-encoded CheATotal no. of particlesNo. of particles in cytoplasmMembrane particlesbNo. of membrane particles/sectionNo. of polar clustersSize of polar clustersdNo. of lateral clustersSize of lateral clustersd
Polar particlescLateral particles
%% in clusters%% in clusters
AJW768NoneCheAL 1,90110494876219.012112.2 ± 0.845.5 ± 1.3
CheAS
AJW776NoneCheALM98L(S−)2,07014491839239.614310.1 ± 0.566.7 ± 0.9
AJW774NoneCheALM98L(S+)2,28428674* 63* 261810.01138.3 ± 0.4146.8 ± 1.1
AJW916CheALM98LNone1,609121898711217.411510.0 ± 0.557.2 ± 1.2
AJW917CheALM98LCheAS 1,818118888712518.511811.0 ± 0.5157.1 ± 0.6
AJW430CheALK616(Am)None1,11611381* 77* 19305.0689.2 ± 0.7105.7 ± 0.6
CheASK616(Am)
AJW530CheALK616(Am)CheAS 1,1881198882* 1495.37310.5 ± 0.734.0
CheASK616(Am)
AJW970NoneCheALG422A2,0151018768* 12279.61288.8 ± 0.5116.2 ± 1.2
CheASG422A
  • a The numbers and positions of gold particles detected by immunomicroscopy from 200 thin sections of cells are shown. The numbers and sizes of gold particle clusters located in either the polar or lateral membrane were determined. The relative size of the clusters ± 1 standard error of the mean is presented. CheA expression was uninduced in AJW768, AJW776, and AJW430 and induced at 10 μM IPTG in all other strains.

  • b The percentages of gold particles at the poles or along the lateral edges and the percentage of polar or lateral gold particles that are clustered are shown.

  • c Strains that are significantly different (P ≤ 0.05) from AJW768 are marked with an asterisk.

  • d Numbers of particles per cluster.