Pho4

From Proteopedia

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spinqualitylabelsall models Yeast Pho4 DNA-binding domain complex with DNA (PDB code 1a0a) Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image Function Phosphate system positive regulatory protein Pho4 is a transcriptional activator which regulates the expression of phosphatase under conditions of phosphate starvation[1]. For details see Pho4 bHLH Protein. . Its structure is a basic basic helix-loop-helix (bHLH) [1] The pho4 protein takes part in transcription of several yeast genes related to phosphate metabolism: PH05- encoding repressible acid phosphatase [2] PH08-encoding alkaline phosphatase [2] PH081-a regulatory gene [3] PH084- phosphate permease gene [4]

sturcture

The structure of the Pho4 protein is a basic Helix-loop-helix(bHLH) , The linker sequence between Helix1(H1) and Helix2(H2) contains several residues: Asn, Glu, Pro and Ser[6]. The DNA binding site is a homodimer and two monomers in a left‐handed four‐helix bundle fold (identical to bHLH/Zip and bHLH proteins fold) [7].

loop structure Pho4 loops (conserved structure?) are long but compact and forms a short alpha-helical structure [5]. The PHO4 loop contains a Trp residue that faces the aromatic rings of Tyr52 and His55 of helix H2, and Pro28 of H2 and H1.an aromatic cluster forms a cap structure is observed.

3D Structures of lactoferrin

Updated on 19-March-2018

1a0a – yPho4 DNA-binding domain + DNA - yeast
3w3x – yPho4 peptide + importin subunit b-3

References

1. ↑ Berben G, Legrain M, Gilliquet V, Hilger F. The yeast regulatory gene PHO4 encodes a helix-loop-helix motif. Yeast. 1990 Sep-Oct;6(5):451-4. PMID:2220078 doi:http://dx.doi.org/10.1002/yea.320060510