Universität zu Köln

Zoellner, Robert, Cronenberg, Tom and Maier, Berenike ORCID: 0000-0001-6971-9927 (2019). Motor Properties of PilT-Independent Type 4 Pilus Retraction in Gonococci. J. Bacteriol., 201 (18). WASHINGTON: AMER SOC MICROBIOLOGY. ISSN 1098-5530

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Abstract

Bacterial type 4 pili (T4P) belong to the strongest molecular machines. The gonococcal T4P retraction ATPase PilT supports forces exceeding 100 pN during T4P retraction. Here, we address the question of whether gonococcal T4P retract in the absence of PilT. We show that pilT deletion strains indeed retract their T4P, but the maximum force is reduced to 5 pN. Similarly, the speed of T4P retraction is lower by orders of magnitude compared to that of T4P retraction driven by PilT. Deleting the pilT paralogue pilT2 further reduces the speed of T4P retraction, yet T4P retraction is detectable in the absence of all three pilT paralogues. Furthermore, we show that depletion of proton motive force (PMF) slows but does not inhibit pilT-independent T4P retraction. We conclude that the retraction ATPase is not essential for gonococcal T4P retraction. However, the force generated in the absence of PilT is too low to support important functions of T4P, including twitching motility, fluidization of colonies, and induction of host cell response. IMPORTANCE Bacterial type 4 pili (T4P) have been termed the Swiss Army knives of bacteria because they perform numerous functions, including host cell interaction, twitching motility, colony formation, DNA uptake, protein secretion, and surface sensing. The pilus fiber continuously elongates or retracts, and these dynamics are functionally important. Curiously, only a subset of T4P systems employ T4P retraction ATPases to power T4P retraction. Here, we show that one of the strongest T4P machines, the gonococcal T4P, retracts without a retraction ATPase. Biophysical characterization reveals strongly reduced force and speed compared to retraction with ATPase. We propose that bacteria encode retraction ATPases when T4P have to generate high-force-supporting functions like twitching motility, triggering host cell response, or fluidizing colonies.

Item Type:	Journal Article
Creators:	Creators Email ORCID ORCID Put Code Zoellner, Robert UNSPECIFIED UNSPECIFIED UNSPECIFIED Cronenberg, Tom UNSPECIFIED UNSPECIFIED UNSPECIFIED Maier, Berenike UNSPECIFIED orcid.org/0000-0001-6971-9927 UNSPECIFIED
URN:	urn:nbn:de:hbz:38-143458
DOI:	10.1128/JB.00778-18
Journal or Publication Title:	J. Bacteriol.
Volume:	201
Number:	18
Date:	2019
Publisher:	AMER SOC MICROBIOLOGY
Place of Publication:	WASHINGTON
ISSN:	1098-5530
Language:	English
Faculty:	Faculty of Mathematics and Natural Sciences
Divisions:	Faculty of Mathematics and Natural Sciences > Department of Physics > Institut für Biologische Physik
Subjects:	no entry
Uncontrolled Keywords:	Keywords Language CORTICAL PLAQUE-FORMATION; IV PILI; DNA-UPTAKE; MOLECULAR-MECHANISM; TWITCHING MOTILITY; FORCE GENERATION; DYNAMICS; TRANSFORMATION Multiple languages Microbiology Multiple languages
Refereed:	Yes
URI:	http://kups.ub.uni-koeln.de/id/eprint/14345