trehalose synthase-fused probable maltokinase. Three pathways for the biosynthesis of trehalose, an osmoprotectant that in some species is also a precursor of certain cell wall glycolipids. Trehalose synthase, TreS, can interconvert maltose and trehalose, but while the equilibrium may favor trehalose, physiological concentrations of trehalose may be much greater than that of maltose and TreS may act largely in its degradation. This model describes a domain found only as a C-terminal fusion to TreS proteins. The most closely related proteins outside this family, Pep2 of Streptomyces coelicolor and Mak1 of Actinoplanes missouriensis, have known maltokinase activity. We suggest this domain acts as a maltokinase and helps drive conversion of trehalose to maltose. [Energy metabolism, Biosynthesis and degradation of polysaccharides]

Predicted trehalose synthase [Carbohydrate transport and metabolism].

glycogen branching enzyme; Provisional

Maltokinase N-terminal cap domain. Glycogen is a central energy storage molecule in bacteria and the metabolic pathways associated with its biosynthesis and degradation are crucial for maintaining cellular energy homeostasis. In mycobacteria, the GlgE pathway involves the combined action of trehalose synthase (TreS), maltokinase (Mak) and maltosyltransferase (GlgE). The N-terminal lobe can be divided into two subdomains: a cap N-terminal subdomain comprising the first 88 amino acid residues. This entry is for the cap N-terminal domain found in mycobacterial maltokinase (Mak), (EC:2.7.1.175). The N-terminal cap subdomain and the C-terminal lobe are predominantly acidic, the intermediate subdomain is enriched in positively charged residues. A structural search with only the first 88 amino acid residues of Mak, corresponding to the N-terminal cap subdomain of maltokinases, unveiled a resemblance with proteins displaying the cystatin fold and a remote similarity with the N-terminal domain of the serine/threonine protein kinase GCN2. Conservation of the cap subdomain in maltokinases (including the bifunctional TreS-Mak enzymes), in particular of the residues in the proximity of the P-loop, together with the potential flexibility of this region, are compatible with regulatory functions for this subdomain. Hence it is hypothesized that the N-terminal cap subdomain plays a central role in modulation of Mak enzymatic activity.

ChainA, Maltokinase [Mycobacterium tuberculosis],4O7O_B Chain B, Maltokinase [Mycobacterium tuberculosis],4O7P_A Chain A, Maltokinase [Mycobacterium tuberculosis],4O7P_B Chain B, Maltokinase [Mycobacterium tuberculosis]

Complexof Mycobacterium smegmatis trehalose synthase with maltokinase [Mycolicibacterium smegmatis MC2 155],5JY7_J Complex of Mycobacterium smegmatis trehalose synthase with maltokinase [Mycolicibacterium smegmatis MC2 155],5JY7_K Complex of Mycobacterium smegmatis trehalose synthase with maltokinase [Mycolicibacterium smegmatis MC2 155],5JY7_L Complex of Mycobacterium smegmatis trehalose synthase with maltokinase [Mycolicibacterium smegmatis MC2 155],5JY7_M Complex of Mycobacterium smegmatis trehalose synthase with maltokinase [Mycolicibacterium smegmatis MC2 155],5JY7_N Complex of Mycobacterium smegmatis trehalose synthase with maltokinase [Mycolicibacterium smegmatis MC2 155],5JY7_O Complex of Mycobacterium smegmatis trehalose synthase with maltokinase [Mycolicibacterium smegmatis MC2 155],5JY7_P Complex of Mycobacterium smegmatis trehalose synthase with maltokinase [Mycolicibacterium smegmatis MC2 155]

Structureof mycobacterial maltokinase, the missing link in the essential GlgE-pathway [Mycolicibacterium vanbaalenii PYR-1],4U98_A Structure of mycobacterial maltokinase, the missing link in the essential GlgE-pathway (AppCp complex) [Mycolicibacterium vanbaalenii PYR-1],4WZY_A Structure of mycobacterial maltokinase, the missing link in the essential GlgE-pathway (ATP complex) [Mycolicibacterium vanbaalenii PYR-1]

Glucosaminekinase (crystal form A) [Streptacidiphilus jiangxiensis],6HWJ_B Glucosamine kinase (crystal form A) [Streptacidiphilus jiangxiensis],6HWK_A Glucosamine kinase (crystal form B) [Streptacidiphilus jiangxiensis],6HWK_B Glucosamine kinase (crystal form B) [Streptacidiphilus jiangxiensis],6HWK_C Glucosamine kinase (crystal form B) [Streptacidiphilus jiangxiensis],6HWK_D Glucosamine kinase (crystal form B) [Streptacidiphilus jiangxiensis],6HWL_A Glucosamine kinase in complex with glucosamine, ADP and inorganic phosphate [Streptacidiphilus jiangxiensis],6HWL_B Glucosamine kinase in complex with glucosamine, ADP and inorganic phosphate [Streptacidiphilus jiangxiensis]

Maltokinase OS=Mycobacterium bovis (strain BCG / Tokyo 172 / ATCC 35737 / TMC 1019) OX=561275 GN=mak PE=3 SV=1

Maltokinase OS=Mycobacterium tuberculosis (strain CDC 1551 / Oshkosh) OX=83331 GN=mak PE=3 SV=1

Maltokinase OS=Mycobacterium bovis (strain ATCC BAA-935 / AF2122/97) OX=233413 GN=mak PE=1 SV=1

Maltokinase OS=Mycobacterium bovis (strain BCG / Pasteur 1173P2) OX=410289 GN=mak PE=3 SV=1

Maltokinase OS=Mycobacterium tuberculosis (strain KZN 1435 / MDR) OX=478434 GN=mak PE=3 SV=1