Identification and characterization of two families of F420 H2-dependent reductases from Mycobacteria that catalyse aflatoxin degradation.
Aflatoxins are polyaromatic mycotoxins that contaminate a range of food crops as a result of fungal growth and contribute to serious health problems in the developing world because of their toxicity and mutagenicity. Although relatively resistant to biotic degradation, aflatoxins can be metabolized by certain species of Actinomycetales. However, the enzymatic basis for their breakdown has not been reported until now. We have identified nine Mycobacterium smegmatis enzymes that utilize the deazaflavin cofactor F(420) H(2) to catalyse the reduction of the α,β-unsaturated ester moiety of aflatoxins, activating the molecules for spontaneous hydrolysis and detoxification. These enzymes belong to two previously uncharacterized F(420) H(2) dependent reductase (FDR-A and -B) families that are distantly related to the flavin mononucleotide (FMN) dependent pyridoxamine 5'-phosphate oxidases (PNPOxs). We have solved crystal structures of an enzyme from each FDR family and show that they, like the PNPOxs, adopt a split barrel protein fold, although the FDRs also possess an extended and highly charged F(420) H(2) binding groove. A general role for these enzymes in xenobiotic metabolism is discussed, including the observation that the nitro-reductase Rv3547 from Mycobacterium tuberculosis that is responsible for the activation of bicyclic nitroimidazole prodrugs belongs to the FDR-A family.
Taylor
Matthew C
MC
CSIRO Ecosystem Sciences, GPO Box 1700, Canberra, ACT 2601, Australia. m.taylor@csiro.au
Jackson
Colin J
CJ
Tattersall
David B
DB
French
Nigel
N
Peat
Thomas S
TS
Newman
Janet
J
Briggs
Lyndall J
LJ
Lapalikar
Gauri V
GV
Campbell
Peter M
PM
Scott
Colin
C
Russell
Robyn J
RJ
Oakeshott
John G
JG
D000348:Aflatoxins / Q000378:metabolism*; D001426:Bacterial Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D002384:Catalysis; D007700:Kinetics; D008958:Models, Molecular; D008969:Molecular Sequence Data; D005810:Multigene Family; D009161:Mycobacterium / Q000145:classification / Q000201:enzymology* / Q000235:genetics / Q000378:metabolism; D010088:Oxidoreductases / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D010802:Phylogeny; D011485:Protein Binding; D012256:Riboflavin / Q000031:analogs & derivatives* / Q000378:metabolism
D000348:Aflatoxins; D001426:Bacterial Proteins; C015084:coenzyme F420; D010088:Oxidoreductases; D012256:Riboflavin
Biosci Biotechnol Biochem. 2004 Jun;68(6):1345-52
15215601
Acta Crystallogr D Biol Crystallogr. 1997 May 1;53(Pt 3):240-55
15299926
Prog Nucleic Acid Res Mol Biol. 2002;71:223-83
12102556
Acta Crystallogr D Biol Crystallogr. 2002 Oct;58(Pt 10 Pt 2):1772-9
12351820
Appl Microbiol. 1966 Nov;14(6):934-9
16349699
Biochemistry. 2001 Sep 11;40(36):10859-72
11535063
Int J Food Microbiol. 2008 May 10;124(1):1-12
18258326
Arch Microbiol. 2003 Dec;180(6):455-64
14593448
FEBS Lett. 2005 Jan 3;579(1):215-21
15620716
Plant Cell Rep. 2007 Apr;26(4):531-8
17031651
J Bacteriol. 1998 Apr;180(8):2212-9
9555906
Nucleic Acids Res. 2001 Jan 1;29(1):123-5
11125067
Nat Protoc. 2009;4(3):363-71
19247286
Appl Environ Microbiol. 2002 Jul;68(7):3371-6
12089017
J Biol Chem. 1961 Jul;236:2089-95
13782387
Protein Expr Purif. 1998 Aug;13(3):349-56
9693059
Acta Crystallogr D Biol Crystallogr. 2006 Jan;62(Pt 1):72-82
16369096
J Mol Biol. 2002 Jan 18;315(3):385-97
11786019
Acta Crystallogr Sect F Struct Biol Cryst Commun. 2006 Aug 1;62(Pt 8):735-42
16880544
Anal Bioanal Chem. 2007 Sep;389(1):147-57
17508207
J Comput Chem. 2003 Oct;24(13):1549-62
12925999
J Agric Food Chem. 1998 Feb 16;46(2):599-605
10554284
Acta Crystallogr D Biol Crystallogr. 2005 Nov;61(Pt 11):1492-9
16239726
Insect Biochem Mol Biol. 2008 Oct;38(10):950-8
18760362
Appl Environ Microbiol. 2002 Nov;68(11):5750-5
12406775
J Bacteriol. 2002 Nov;184(22):6115-22
12399480
Microbiology (Reading). 2002 Sep;148(Pt 9):2687-2695
12213915
Int J Food Microbiol. 2005 Nov 25;105(2):111-7
16061299
Bioinformatics. 2008 Dec 1;24(23):2780-1
18818215
Crit Rev Food Sci Nutr. 2003;43(3):245-64
12822672
Acta Crystallogr Sect F Struct Biol Cryst Commun. 2008 May 1;64(Pt 5):435-7
18453720
J Biol Chem. 2010 Jun 18;285(25):19135-44
20075070
J Bacteriol. 2002 May;184(9):2420-8
11948155
Experientia. 1981 Jan 15;37(1):16-7
6781926
J Food Prot. 2000 Mar;63(3):415-8
10716576
Syst Appl Microbiol. 2004 Nov;27(6):653-60
15612622
Acta Crystallogr D Biol Crystallogr. 2001 Oct;57(Pt 10):1445-50
11567158
Arch Biochem Biophys. 1968 Jun;125(3):802-8
5671043
Science. 2008 Nov 28;322(5906):1392-5
19039139
Appl Environ Microbiol. 2007 Mar;73(5):1622-9
17209063
Biochim Biophys Acta. 1995 Mar 15;1247(2):265-71
7696318
Microbiology (Reading). 2007 Aug;153(Pt 8):2724-2732
17660436
Proc Natl Acad Sci U S A. 2006 Jan 10;103(2):431-6
16387854
Nat Prod Rep. 2002 Apr;19(2):133-47
12013276
Acta Crystallogr D Biol Crystallogr. 2006 Jan;62(Pt 1):48-57
16369093
J Biol Chem. 1958 Jun;232(2):761-76
13549461
Acta Crystallogr D Biol Crystallogr. 2004 Dec;60(Pt 12 Pt 1):2126-32
15572765
J Bacteriol. 1996 May;178(10):2861-6
8631674
J Appl Microbiol. 2008 Dec;105(6):2153-60
19016976
J Biol Chem. 2005 Nov 18;280(46):38776-86
16048999
Mol Biol Evol. 2007 Aug;24(8):1596-9
17488738
Acta Crystallogr D Biol Crystallogr. 2005 May;61(Pt 5):599-604
15858270
FEMS Microbiol Lett. 1997 Jan 1;146(1):129-34
8997717
Biochim Biophys Acta. 1981 Apr 3;673(4):570-93
6894393
J Biol Chem. 2008 Jun 20;283(25):17531-41
18434308
Antonie Van Leeuwenhoek. 2008 Jun;94(1):11-9
18418729
Environ Biosafety Res. 2008 Oct-Dec;7(4):197-218
19081008
Methods Enzymol. 2005;401:78-99
16399380
Microb Ecol. 2004 Aug;48(2):230-8
15107954
Poult Sci. 2008 Aug;87(8):1569-76
18648051
Appl Microbiol Biotechnol. 2001 Aug;56(3-4):539-44
11549034
Nucleic Acids Res. 2010 Jul;38(Web Server issue):W555-62
20478824
Nucleic Acids Res. 2007 Jan;35(Database issue):D237-40
17135202
Biochim Biophys Acta. 2003 Apr 11;1647(1-2):76-82
12686112
Phytother Res. 2005 Nov;19(11):938-41
16317649
Int J Food Microbiol. 2006 May 25;109(1-2):121-6
16504326
J Appl Microbiol. 2002;93(3):380-9
12174035
Biodegradation. 2001;12(5):367-76
11995829