The Structure of the Holo-Acyl Carrier Protein of Leishmania major Displays a Remarkably Different Phosphopantetheinyl Transferase Binding Interface

Kumar, Ambrish and Arya, Richa and Makwana, Pinakin K and Dangi, Rohit Singh and Yadav, Usha and Surolia, Avadhesha and Kundu, Suman and Sundd, Monica (2015) The Structure of the Holo-Acyl Carrier Protein of Leishmania major Displays a Remarkably Different Phosphopantetheinyl Transferase Binding Interface. In: BIOCHEMISTRY, 54 (36). pp. 5632-5645.

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Abstract

The genome of Leishmania major encodes a type II fatty acid biosynthesis pathway for which no structural or biochemical information exists. Here, for the first time, we have characterized the central player of the pathway, the acyl carrier protein (LmACP), using nuclear magnetic resonance (NMR). Structurally, the LmACP molecule is similar to other type II ACPs, comprising a four-helix bundle, enclosing a hydrophobic core. Dissimilarities in sequence, however, exist in helix II (recognition helix) of the protein. The enzymatic conversion of apo-LmACP into the holo form using type I (Escherichia coli AcpS) and type II (Sfp type) phosphopantetheinyl transferases (PPTs) is relatively slow. Mutagenesis studies underscore the importance of the residues present at the protein protein interaction interface of LmACP in modulating the activity of PPTs. Interestingly, the cognate PPT for this ACP, the L. major 4'-phosphopantetheinyl transferase (LmPPT), does not show any enzymatic activity toward it, though it readily converts other type I and type II ACPs into their holo forms. NMR chemical shift perturbation studies suggest a moderately tight complex between LmACP and its cognate PPT, suggesting inhibition. We surmise that the unique surface of LmACP might have evolved to complement its cognate enzyme (LmPPT), possibly for the purpose of regulation.

Item Type:	Journal Article
Publication:	BIOCHEMISTRY
Publisher:	AMER CHEMICAL SOC
Additional Information:	Copy right for this article belongs to the AMER CHEMICAL SOC, 1155 16TH ST, NW, WASHINGTON, DC 20036 USA
Department/Centre:	Division of Biological Sciences > Molecular Biophysics Unit
Date Deposited:	15 Oct 2015 06:15
Last Modified:	15 Oct 2015 06:15
URI:	http://eprints.iisc.ac.in/id/eprint/52552

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