3DSG

XC1028 from Xanthomonas campestris Adopts a PilZ Domain-like Structure Yet with Trivial c-di-GMP Binding Activity

Summary for 3DSG

• Entry DOI: 10.2210/pdb3dsg/pdb
• Descriptor: Type IV fimbriae assembly protein (2 entities in total)
• Functional Keywords: pilz domain, xanthomonas campestris, c-di-gmp, type iv pilus, pa2960, unknown function
• Biological source: Xanthomonas campestris pv. campestris
• Total number of polymer chains: 3
• Total formula weight: 31646.59

Authors

Li, T.N.,Chin, K.H.,Liu, J.H.,Wang, A.H.J.,Chou, S.H. (deposition date: 2008-07-12, release date: 2009-05-19, Last modification date: 2024-10-30)

Primary citation

Li, T.N.,Chin, K.H.,Liu, J.H.,Wang, A.H.,Chou, S.H.
XC1028 from Xanthomonas campestris adopts a PilZ domain-like structure without a c-di-GMP switch.
Proteins, 75:282-288, 2009

PubMed Abstract: The crystal structure of XC1028 from Xanthomonas campestris has been determined to a resolution of 2.15 A using the multiple anomalous dispersion approach. It bears significant sequence identity and similarity values of 64.10% and 70.09%, respectively, with PA2960, a protein indispensable for type IV pilus-mediated twitching motility, after which the PilZ motif was first named. However, both XC1028 and PA2960 lack detectable c-di-GMP binding capability. Although XC1028 adopts a structure comprising a five-stranded beta-barrel core similar to other canonical PilZ domains with robust c-di-GMP binding ability, considerable differences are observed in the N-terminal motif; XC1028 assumes a compact five-stranded beta-barrel without an extra long N-terminal motif, whereas other canonical PilZ domains contain a long N-terminal sequence embedded with an essential "c-di-GMP switch" motif. In addition, a beta-strand (beta1) in the N-terminal motif, running in exactly opposite polarity to that of XC1028, is found inserted into the parallel beta3/beta1' strands, forming a completely antiparallel beta4 downward arrow beta3 upward arrow beta1 downward arrow beta1' upward arrow sheet in the canonical PilZ domains. Such dramatic structural differences at the N-terminus may account for the diminished c-di-GMP binding capability of XC1028, and suggest that interactions with additional proteins are necessary to bind c-di-GMP for type IV fimbriae assembly.

PubMed: 19127589
DOI: 10.1002/prot.22330

Experimental method

X-RAY DIFFRACTION (2.09 Å)