Lysine-N-oxygenase MbtG (L-lysine 6-monooxygenase) (lysine N6-hydroxylase); Flavoprotein monooxygenase required for N-hydroxylation of the two acylated lysine residues during mycobactin assembly, thus producing the hydroxamate groups necessary for iron sequestration. Is also able, but less efficiently, to hydroxylate L-lysine (non acylated) in vitro.

Polyketide synthetase MbtC (polyketide synthase); Rv2382c, (MTCY22H8.03), len: 444 aa. MbtC,polyketide synthase (see citations below), similar in part to several synthases e.g. Q9F7T9 avermectin polyketide synthase (fragment) from Streptomyces avermitilis (3626 aa), FASTA scores: opt: 1458, E(): 7e-82, (50.65% identity in 446 aa overlap); AAG23264|SPNA polyketide synthase loading and extender module 1 from Saccharopolyspora spinosa (2595 aa) FASTA scores: opt: 1441, E(): 6e-81,(49.1% identity in 446 aa overlap); O33954|TYLG tylactone synthase starter module and modules 1 & 2 from Strep [...]

Polyketide synthetase MbtD (polyketide synthase); Rv2381c, (MTCY22H8.04), len: 1004 aa. MbtD,polyketide synthase (see citations below), similar in part to several synthases e.g. Q03132|ERY2_SACER|ERYA erythronolide synthase, modules 3 and 4 from Saccharopolyspora erythraea (Streptomyces erythraeus) (3567 aa), FASTA scores: opt: 971, E(): 1e-46, (29.35% identity in 1043 aa overlap); Q9F829|megaii megalomicin 6-deoxyerythronolide B synthase 2 from Micromonospora megalomicea subsp. nigra (3562 aa), FASTA scores: opt: 787,E(): 2.4e-36, (29.35% identity in 1032 aa overlap); Q9L4W4|NYSB poly [...]

Rv2380c, (MTCY22H8.05), len: 1682 aa. MbtE, peptide synthetase (see citations below), similar in part to several synthases e.g. O07944|SNBDE pristinamycin I synthase 3 and 4 from Streptomyces pristinaespiralis (4848 aa), FASTA scores: opt: 2635, E(): 1.9e-146, (36.8% identity in 1657 aa overlap); O05647|SNBDE virginiamycin S synthetase (fragment) from Streptomyces virginiae (1997 aa) FASTA scores: opt: 2580, E(): 1.6e-143, (40.65% identity in 1163 aa overlap); Q9R9I2|DHBF protein involved in siderophore production from Bacillus subtilis (2378 aa),FASTA scores: opt: 2388, E(): 3.6e-132, [...]

Phenyloxazoline synthase MbtB (phenyloxazoline synthetase); Involved in the initial steps of the mycobactin biosynthetic pathway. Putatively couples activated salicylic acid with serine or threonine and cyclizes this precursor to the hydroxyphenyloxazoline ring system present in this class of siderophores. Essential for growth in macrophages; Belongs to the ATP-dependent AMP-binding enzyme family. MbtB subfamily.

Bifunctional enzyme MbtA: salicyl-AMP ligase (SAL-AMP ligase) + salicyl-S-ArCP synthetase; Involved in the initial steps of the mycobactin biosynthetic pathway. Catalyzes the salicylation of the aryl carrier protein (ArCP) domain of MbtB through a two-step reaction. The first step is the ATP- dependent adenylation of salicylate to generate a salicyl-AMP intermediate. The second step is the transfer of this activated salicylate to MbtB to form a salicyl-ArCP domain thioester.

Isochorismate synthase MbtI; Involved in the incorporation of salicylate into the virulence-conferring salicylate-based siderophore mycobactin. Catalyzes the initial conversion of chorismate to yield the intermediate isochorismate (isochorismate synthase activity), and the subsequent elimination of the enolpyruvyl side chain to give salicylate (isochorismate pyruvate-lyase activity). In the absence of magnesium, MbtI displays a chorismate mutase activity and converts chorismate to prephenate.

Probable fatty-acid-AMP ligase FadD24 (fatty-acid-AMP synthetase) (fatty-acid-AMP synthase); Rv1529, (MTV045.03), len: 584 aa. Probable fadD24,fatty-acid-AMP synthetase, highly similar to many e.g. MBU75685_1|AAB52538.1|U75685 acyl-CoA synthase from Mycobacterium bovis (582 aa), FASTA score: (65.6% identity in 582 aa overlap); and many other fatty-acid-CoA synthetases from Mycobacteria e.g. fadD25|MTCY19G5_7 from Mycobacterium tuberculosis (583 aa), FASTA score: (68.7% identity in 584 aa overlap); fadD28|MTCY24G1_8 from Mycobacterium tuberculosis (580 aa), FASTA score: (66.0% identity [...]