5IP0

PHA Binding Protein PhaP (Phasin)

Summary for 5IP0

• Entry DOI: 10.2210/pdb5ip0/pdb
• Descriptor: PHA granule-associated protein, CADMIUM ION (2 entities in total)
• Functional Keywords: phb, polyhydroxyalkanoates, phap, biosurfactant, amphiphilicity, point mutation, emulsification, structural protein
• Biological source: Aeromonas hydrophila
• Total number of polymer chains: 16
• Total formula weight: 205761.17

Authors

Chen, G.Q.,Wang, X.Q.,Zhao, H.Y. (deposition date: 2016-03-09, release date: 2017-01-25, Last modification date: 2024-03-20)

Primary citation

Zhao, H.,Wei, H.,Liu, X.,Yao, Z.,Xu, M.,Wei, D.,Wang, J.,Wang, X.,Chen, G.Q.
Structural Insights on PHA Binding Protein PhaP from Aeromonas hydrophila
Sci Rep, 6:39424-39424, 2016

PubMed Abstract: Phasins or PhaPs are a group of amphiphilic proteins that are found attached to the surface of microbial polyhydroxyalkanoate (PHA) granules. They have both structural and regulatory functions and can affect intracellular PHA accumulation and mediate protein folding. The molecular basis for the diverse functions of the PhaPs has not been fully understood due to the lack of the structural knowledge. Here we report the structural and biochemical studies of the PhaP cloned from Aeromonas hydrophila (PhaP), which is utilized in protein and tissue engineering. The crystal structure of PhaP was revealed to be a tetramer with 8 α-helices adopting a coiled-coil structure. Each monomer has a hydrophobic and a hydrophilic surface, rendering the surfactant properties of the PhaP monomer. Based on the crystal structure, we predicted three key amino acid residues and obtained mutants with enhanced stability and improved emulsification properties. The first PhaP crystal structure, as reported in this study, is an important step towards a mechanistic understanding of how PHA is formed in vivo and why PhaP has such unique surfactant properties. At the same time, it will facilitate the study of other PhaP members that may have significant biotechnological potential as bio-surfactants and amphipathic coatings.

PubMed: 28009010
DOI: 10.1038/srep39424

Experimental method

X-RAY DIFFRACTION (3 Å)