Probable polyketide beta-ketoacyl synthase Pks4; Polyketide synthase involved in the biosynthesis of methyl- branched fatty acids such as mycolipanoic, mycolipenic (phthienoic) and mycolipodienoic acids required for the synthesis of a major class of polyacylated trehaloses. Catalyzes the elongation of CoA esters of long-chain fatty acids by incorporation of three methylmalonyl (but not malonyl) residues, to form trimethyl-branched fatty-acids.

Rv1663, (MTCY275.02), len: 502 aa. Probable pks17,polyketide synthase, similar to other polyketide synthases e g. ERY2_SACER|Q03132 erythronolide synthase, modules 3 and 4 (3567 aa) from Saccharopolyspora erythraea (Streptomyces erythraeus), FASTA scores: opt: 1207, E(): 0,(43.9% identity in 531 aa overlap). Also similar to other Mycobacterium tuberculosis probable polyketide synthases e.g. pks7 and pks1. Note that the similarity extends into the upstream ORF Rv1662 (MTCY275.01) and this could be accounted for by a frameshift, although the sequence has been checked and no discrepancy w [...]

P-hydroxybenzoyl-AMP ligase FadD22; Catalyzes the adenylation of p-hydroxybenzoic acid (pHBA) to form p-hydroxybenzoic acid-AMP (pHBA-AMP), which is converted directly to p-hydroxybenzoyl-S-FadD22 (pHBA-S-FAdD22) thioester intermediate in a CoA-independent manner by attack of the phosphopantetheine thiol of FadD22. Usually, this intermediate primes the biosynthesis of the phenolphthiocerol (PPOL) by presenting the pHBA starter unit for elongation by Pks15/1, but M.tuberculosis lacks Pks15/1 due to a natural frameshift and thus is unable to produce PPOL. Belongs to the ATP-dependent AMP [...]

Fatty-acid-AMP ligase FadD29 (fatty-acid-AMP synthetase) (fatty-acid-AMP synthase); Catalyzes the activation of the long-chain fatty acids (C22- 24 fatty acids) as acyl-adenylates (acyl-AMP), which are then transferred to the multifunctional polyketide synthase PpsA for further chain extension. Involved in the biosynthesis of phenolphthiocerol, which is an important intermediate in the biosynthesis of phenolic glycolipid (mycosid B).

Chorismate pyruvate lyase; Removes the pyruvyl group from chorismate to provide 4- hydroxybenzoate (4HB). Involved in the synthesis of glycosylated p- hydroxybenzoic acid methyl esters (p-HBADs) and phenolic glycolipids (PGL) that play important roles in the pathogenesis of mycobacterial infections.

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.

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, [...]

Rv3141, (MTCY03A2.17c), len: 323 aa. Probable fadB4,quinone oxidoreductase, showing strong similarity to variety of quinone oxidoreductases and domains in polyketide and fatty acid synthases e.g. Q9HTV6|PA5234 probable oxidoreductase from Pseudomonas aeruginosa (325 aa), FASTA scores: opt: 737, E(): 1.4e-35, (39.65% identity in 328 aa overlap); Q9RYQ7|DRA0251 putative NADPH quinone oxidoreductase from Deinococcus radiodurans (336 aa), FASTA scores: opt: 688, E(): 1e-32, (40.6% identity in 325 aa overlap); Q9RVG8|DR1061 putative NADPH quinone oxidoreductase from Deinococcus radiodurans [...]

Rv3777, (MTCY13D12.11), len: 328 aa. Probable oxidoreductase, equivalent to Q9CD96|ML0118 putative oxidoreductase from Mycobacterium leprae (336 aa) FASTA scores: opt: 1661, E(): 1.1e-87, (76.0% identity in 325 aa overlap). Also highly similar to many e.g. Q9XA55|SCGD3.24c putative quinone oxidoreductase from Streptomyces coelicolor (326 aa) FASTA scores: opt: 1118, E(): 1.3e-64,(59.6% identity in 312 aa overlap); O65423|F18E5.200|F17L22.40|AT4G21580 putative NADPH quinone oxidoreductase from Arabidopsis thaliana (Mouse-ear cress) (325 aa), FASTA scores: opt: 1110, E(): 3e-56, (52.15% [...]