7EL2

Crystal structure of apo-HpaR from Acinetobacter baumannii

Summary for 7EL2

• Entry DOI: 10.2210/pdb7el2/pdb
• Related: 7EL3
• Descriptor: Homoprotocatechuate degradation operon regulator HpaR (2 entities in total)
• Functional Keywords: marr family of transcription regulators, transcription factor in hpa-degradation pathway, acinetobacter baumannii, dna binding protein
• Biological source: Acinetobacter baumannii
• Total number of polymer chains: 2
• Total formula weight: 33008.59

Authors

Permsirivisarn, P.,Pakotiprapha, D. (deposition date: 2021-04-07, release date: 2022-01-19, Last modification date: 2023-11-29)

Primary citation

Permsirivisarn, P.,Yuenyao, A.,Pramanpol, N.,Charoenwattanasatien, R.,Suginta, W.,Chaiyen, P.,Pakotiprapha, D.
Mechanism of transcription regulation by Acinetobacter baumannii HpaR in the catabolism of p-hydroxyphenylacetate.
Febs J., 289:3217-3240, 2022

PubMed Abstract: HpaR is a transcription regulator in the MarR family that controls the expression of the gene cluster responsible for conversion of p-hydroxyphenylacetate to pyruvate and succinate for cellular metabolism. Here, we report the biochemical and structural characterization of Acinetobacter baumannii HpaR (AbHpaR) and its complex with cognate DNA. Our study revealed that AbHpaR binds upstream of the divergently transcribed hpaA gene and the meta-cleavage operon, as well as the hpaR gene, thereby repressing their transcription by blocking access of RNA polymerase. Structural analysis of AbHpaR-DNA complex revealed that the DNA binding specificity can be achieved via a combination of both direct and indirect DNA sequence readouts. DNA binding of AbHpaR is weakened by 3,4-dihydroxyphenylacetate (DHPA), which is the substrate of the meta-cleavage reactions; this likely leads to expression of the target genes. Based on our findings, we propose a model for how A. baumannii controls transcription of HPA-metabolizing genes, which highlights the independence of global catabolite repression and could be beneficial for metabolic engineering toward bioremediation applications. DATABASES: The structural data that support these findings are openly available in the wwPDB at https://doi.org/10.2210/pdb7EL2/pdb and https://doi.org/10.2210/pdb7EL3/pdb for AbHpaR and AbHpaR-DNA complex, respectively.

PubMed: 34967505
DOI: 10.1111/febs.16340

Experimental method

X-RAY DIFFRACTION (2.2 Å)