6AEF

PapA2 acyl transferase

Summary for 6AEF

• Entry DOI: 10.2210/pdb6aef/pdb
• Descriptor: Trehalose-2-sulfate acyltransferase PapA2, ZINC ION, ACETATE ION, ... (5 entities in total)
• Functional Keywords: mycobacterium tuberculesis papa2 acyl transferase polyketide synthase associated protein, transferase
• Biological source: Mycobacterium tuberculosis (strain ATCC 25618 / H37Rv)
• Total number of polymer chains: 2
• Total formula weight: 104663.66

Authors

Chaudhary, S.,Rao, V.,Panchal, V. (deposition date: 2018-08-04, release date: 2019-06-05, Last modification date: 2023-11-22)

Primary citation

Panchal, V.,Jatana, N.,Malik, A.,Taneja, B.,Pal, R.,Bhatt, A.,Besra, G.S.,Thukral, L.,Chaudhary, S.,Rao, V.
A novel mutation alters the stability of PapA2 resulting in the complete abrogation of sulfolipids in clinical mycobacterial strains.
Faseb Bioadv, 1:306-319, 2019

PubMed Abstract: The analysis of whole genomes has revealed specific geographical distribution of (Mtb) strains across the globe suggestive of unique niche dependent adaptive mechanisms. We provide an important correlation of a genome-based mutation to a molecular phenotype across two predominant clinical Mtb lineages of the Indian subcontinent. We have identified a distinct lineage specific mutation-G247C, translating into an alanine-proline conversion in the A2 gene of Indo-oceanic lineage 1 (L1) Mtb strains, and restoration of cell wall sulfolipids by simple genetic complementation of 2 from lineage 3 (L3) or from H37Rv (lineage 4-L4) attributed the loss of this glycolipid to this specific mutation in Indo-Oceanic L1 Mtb. The investigation of structure of Mtb PapA2 revealed a distinct nonribosomal peptide synthetase (NRPS) C domain conformation with an unconventional presence of a zinc binding motif. Surprisingly, the A83P mutation did not map to either the catalytic center in the N-terminal subdomain or any of the substrate-binding region of the protein. On the contrary, the inherent ability of mutant PapA2 to form insoluble aggregates and molecular simulations with the wild-type/mutant (Wt/mut) PapA2 purports an important role for the surface associated 83rd residue in protein conformation. This study demonstrates the importance of a critical structural residue in the papA2 protein of Mtb and helps establish a link between observed genomic alteration and its molecular consequence in the successful human pathogen Mtb. We demonstrate the effect of a unique SNP in gene of Indo-oceanic (Mtb) strains leading to the loss of sulfolipid from these strains. By X-ray crystallographic analysis and molecular dynamics (MD) simulations, we show the importance of this residue in the global PapA2 structure. The presence of a Zn atom has not been reported before for this class of proteins. Here, we provide an important link between genomic alteration and its molecular consequence in Mtb highlighting one of the many adaptive mechanisms that have contributed to its success as a human pathogen. A high degree of identity with PapA1, 3, or 4 would help in interpreting the structure of these PapA proteins and other acyl transferases of other biological systems.

PubMed: 32123834
DOI: 10.1096/fba.2018-00039

Experimental method

X-RAY DIFFRACTION (2.16 Å)