Abstract
Some bacterial type II fatty-acid synthesis (FAS II) enzymes have been shown to be important candidates for drug discovery. The scientific and medical quest for new FAS II protein targets continues to stimulate research in this field. One of the possible additional candidates is the acyl-carrier-protein synthase (AcpS) enzyme. Its holo form post-translationally modifies the apo form of an acyl carrier protein (ACP), which assures the constant delivery of thioester intermediates to the discrete enzymes of FAS II. At the Center for Structural Genomics of Infectious Diseases (CSGID), AcpSs from Staphylococcus aureus (AcpS(SA)), Vibrio cholerae (AcpS(VC)) and Bacillus anthracis (AcpS(BA)) have been structurally characterized in their apo, holo and product-bound forms, respectively. The structure of AcpS(BA) is emphasized because of the two 3',5'-adenosine diphosphate (3',5'-ADP) product molecules that are found in each of the three coenzyme A (CoA) binding sites of the trimeric protein. One 3',5'-ADP is bound as the 3',5'-ADP part of CoA in the known structures of the CoA-AcpS and 3',5'-ADP-AcpS binary complexes. The position of the second 3',5'-ADP has never been described before. It is in close proximity to the first 3',5'-ADP and the ACP-binding site. The coordination of two ADPs in AcpS(BA) may possibly be exploited for the design of AcpS inhibitors that can block binding of both CoA and ACP.
Highlights
Pathogenic microorganisms, including Staphylococcus aureus, Bacillus anthracis and Vibrio cholerae, remain a serious threat to human life owing to the infections that they cause and their increasing resistance to current antibiotics
AcpSs from Staphylococcus aureus (AcpSSA), AcpSVC and AcpSBA were cloned into the pMCSG7 vector with an N-terminal six-His tag, expressed in E. coli BL21-CodonPlus(DE3) cells and purified using the immobilized metal-affinity chromatography technique as described previously (Graslund et al, 2008)
Crystals suitable for structure determination were obtained under the following conditions: 800 mM succinate pH 7.0 at 295 K for AcpSSA (7.3 mg mlÀ1), 25% PEG 3350, 200 mM MgCl, 100 mM HEPES pH 7.5, 10 mM coenzyme A (CoA) at 295 K for AcpSBA (13.8 mg mlÀ1) and 30% MPD, 100 mM sodium acetate pH 4.6, 20 mM CaCl2, 10 mM CoA at 289 K for AcpSVC (55 mg mlÀ1)
Summary
Pathogenic microorganisms, including Staphylococcus aureus, Bacillus anthracis and Vibrio cholerae, remain a serious threat to human life owing to the infections that they cause and their increasing resistance to current antibiotics. The type II fattyacid synthesis (FAS II) pathway of these bacteria has attracted scientific and medical research and provides multiple targets for drug discovery, since the fatty-acid products of this enzymatic network play a vital role in the life cycle of the pathogens (Maier et al, 2006). There are contradictory data about whether FAS II of the Gram-positive bacteria may be an effective drug target (Wang et al, 2006, 2007; Zhang & Rock, 2008; Brinster et al, 2009; Campbell & Cronan, 2001), since the pathogens can utilize exogenous fatty acids in human serum and their uptake can overcome inhibition (Brinster et al, 2009). Further complications are that FAS I has been found in Mycobacterium tuberculosis (Schweizer & Hofmann, 2004) and FAS II enzymes are present in eukaryotic mitochondria (Chuman & Brody, 1989; Schneider, Brors, Burger et al, 1997; Schneider, Brors, Massow et al, 1997; Miinalainen et al, 2003; Brody et al, 1997)
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callMore From: Acta crystallographica. Section D, Biological crystallography
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
