@article{Raynaud:2021:10.1073/pnas.2102092118,
author = {Raynaud, C and Sheppard, D and Berry, J and Gurung, I and Pelicic, V},
doi = {10.1073/pnas.2102092118},
journal = {Proceedings of the National Academy of Sciences of USA},
pages = {1--10},
title = {PilB from Streptococcus sanguinis is a bimodular type IV pilin with a direct role in adhesion},
url = {http://dx.doi.org/10.1073/pnas.2102092118},
volume = {118},
year = {2021}
}

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TY  - JOUR
AB  - Type IV pili (T4P) are functionally versatile filamentous nanomachines, nearly ubiquitous in prokaryotes. They are predominantly polymers of one major pilin but also contain minor pilins whose functions are often poorly defined and likely to be diverse. Here, we show that the minor pilin PilB from the T4P of Streptococcus sanguinis displays an unusual bimodular three-dimensional structure with a bulky von Willebrand factor A–like (vWA) module “grafted” onto a small pilin module via a short loop. Structural modeling suggests that PilB is only compatible with a localization at the tip of T4P. By performing a detailed functional analysis, we found that 1) the vWA module contains a canonical metal ion–dependent adhesion site, preferentially binding Mg2+ and Mn2+, 2) abolishing metal binding has no impact on the structure of PilB or piliation, 3) metal binding is important for S. sanguinis T4P–mediated twitching motility and adhesion to eukaryotic cells, and 4) the vWA module shows an intrinsic binding ability to several host proteins. These findings reveal an elegant yet simple evolutionary tinkering strategy to increase T4P functional versatility by grafting a functional module onto a pilin for presentation by the filaments. This strategy appears to have been extensively used by bacteria, in which modular pilins are widespread and exhibit an astonishing variety of architectures.
AU  - Raynaud,C
AU  - Sheppard,D
AU  - Berry,J
AU  - Gurung,I
AU  - Pelicic,V
DO  - 10.1073/pnas.2102092118
EP  - 10
PY  - 2021///
SN  - 0027-8424
SP  - 1
TI  - PilB from Streptococcus sanguinis is a bimodular type IV pilin with a direct role in adhesion
T2  - Proceedings of the National Academy of Sciences of USA
UR  - http://dx.doi.org/10.1073/pnas.2102092118
UR  - https://www.pnas.org/content/118/22/e2102092118
UR  - http://hdl.handle.net/10044/1/89303
VL  - 118
ER  - 

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