1.B.1.7.2 Sugar-specific chitoporin of 375 aas, ChiP. The best substrate is chitohexose, but ChiP transports a variety of chitooligosaccharides. Trp136 is important for the
binding affinity for
chitohexaose (Chumjan et al. 2015). X-ray crystal structures of ChiP from V. harveyi in the presence and
absence of chito-oligosaccharides have been solved (Aunkham et al. 2018). Structures without bound sugar reveal
a trimeric assembly with an unprecedented closing of the transport pore
by the N-terminus of a neighboring subunit. Substrate binding ejects
the pore plug to open the transport channel.The structures explain the exceptional affinity of ChiP for
chito-oligosaccharides and point to an important role of the N-terminal
gate in substrate transport (Aunkham et al. 2018). Hydrogen-bonds contribute to sugar permeation (Chumjan et al. 2019). This protein is 90% identical to the chitoporin of the Vibrio campbellii chitoporin (Aunkham et al. 2020). The C2 entity of chitosugars is crucial for the molecular selectivity of the Vibrio campbellii chitoporin (Suginta et al. 2021).
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Accession Number: | L0RVU0 |
Protein Name: | Chitoporin |
Length: | 375 |
Molecular Weight: | 41089.00 |
Species: | Vibrio harveyi [669] |
Number of TMSs: | 1 |
Substrate |
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1: MASYLKKSLL ATAITGMMFS GSAFADGANS DAAKEYLTKD SFSYEVYGII AMQAAYRDYD
61: SGDAKQDDNL GGMQLNNESR IGFRGKKQFA NFEPTFIWQI EGGYVDPSFG GEGAGLGERD
121: TFVGFESASW GQVRLGRVLT PMYELVDWPA SNPGLGDVYD WGGAIGGAKY QDRQSNTIRW
181: DSPMYADKFS IDAAVGAGDK AGLGAGDDYW GGIAAHYKLG PLQLDAAYEG NRNIEAEGQT
241: WENNTYLVGV QGWFENGISF FAQYKYMEAD ASNGVNEKQD AMSAGLMYTT GDWQYKLGYA
301: ANFDLERDGK TLSNTSDDVV SAQIMYFVDP SAVLYARARM NDFNEGLDGL DDAARWTSGT
361: NGDYNEYSVG VEYYF