Structure of the competence pilus major pilin ComGC in Streptococcus pneumoniae

TY - JOUR

T1 - Structure of the competence pilus major pilin ComGC in Streptococcus pneumoniae

AU - Muschiol, Sandra

AU - Erlendsson, Simon

AU - Aschtgen, Marie-Stephanie

AU - Oliveira, Vitor

AU - Schmieder, Peter

AU - de Lichtenberg, Casper

AU - Teilum, Kaare

AU - Boesen, Thomas

AU - Akbey, Umit

AU - Henriques-Normark, Birgitta

PY - 2017/8/25

Y1 - 2017/8/25

N2 - Type IV pili are important virulence factors on the surface of many pathogenic bacteria and have been implicated in a wide range of diverse functions, including attachment, twitching motility, biofilm formation, and horizontal gene transfer. The respiratory pathogen Streptococcus pneumoniae deploys type IV pili to take up DNA during transformation. These "competence pili" are composed of the major pilin proteinComGCand exclusively assembled during bacterial competence, but their biogenesis remains unclear. Here, we report the high resolution NMR structure of N-terminal truncated ComGC revealing a highly flexible and structurally divergent type IV pilin. It consists of only three α-helical segments forming a well-defined electronegative cavity and confined electronegative and hydrophobic patches. The structure is particularly flexible between the first and second α-helix with the first helical part exhibiting slightly slower dynamics than the rest of the pilin, suggesting that the first helix is involved in forming the pilus structure core and that parts of helices two and three are primarily surface-exposed. Taken together, our results provide the first structure of a type IV pilin protein involved in the formation of competence-induced pili in Gram-positive bacteria and corroborate the remarkable structural diversity among type IV pilin proteins.

AB - Type IV pili are important virulence factors on the surface of many pathogenic bacteria and have been implicated in a wide range of diverse functions, including attachment, twitching motility, biofilm formation, and horizontal gene transfer. The respiratory pathogen Streptococcus pneumoniae deploys type IV pili to take up DNA during transformation. These "competence pili" are composed of the major pilin proteinComGCand exclusively assembled during bacterial competence, but their biogenesis remains unclear. Here, we report the high resolution NMR structure of N-terminal truncated ComGC revealing a highly flexible and structurally divergent type IV pilin. It consists of only three α-helical segments forming a well-defined electronegative cavity and confined electronegative and hydrophobic patches. The structure is particularly flexible between the first and second α-helix with the first helical part exhibiting slightly slower dynamics than the rest of the pilin, suggesting that the first helix is involved in forming the pilus structure core and that parts of helices two and three are primarily surface-exposed. Taken together, our results provide the first structure of a type IV pilin protein involved in the formation of competence-induced pili in Gram-positive bacteria and corroborate the remarkable structural diversity among type IV pilin proteins.

KW - microbiology

KW - nuclear magnetic resonance (NMR)

KW - protein structure

KW - transformation

KW - type IV pili

KW - Streptococcus pneumoniae

KW - horizontal gene transfer

KW - major pilin

KW - pneumococci

KW - RESIDUAL DIPOLAR COUPLINGS

KW - IV PILUS

KW - NATURAL TRANSFORMATION

KW - NEISSERIA-GONORRHOEAE

KW - ELECTRON-MICROSCOPY

KW - TWITCHING MOTILITY

KW - ESCHERICHIA-COLI

KW - VIBRIO-CHOLERAE

KW - NMR RELAXATION

KW - DNA-BINDING

UR - http://www.scopus.com/inward/record.url?scp=85028395714&partnerID=8YFLogxK

U2 - 10.1074/jbc.M117.787671

DO - 10.1074/jbc.M117.787671

M3 - Journal article

C2 - 28659339

SN - 0021-9258

VL - 292

SP - 14134

EP - 14146

JO - Journal of Biological Chemistry

JF - Journal of Biological Chemistry

IS - 34

ER -