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The structure of NtdA, a sugar aminotransferase involved in the kanosamine biosynthetic pathway in Bacillus subtilis, reveals a new subclass of aminotransferases.

ABSTRACT: NtdA from Bacillus subtilis is a sugar aminotransferase that catalyzes the pyridoxal phosphate-dependent equatorial transamination of 3-oxo-?-D-glucose 6-phosphate to form ?-D-kanosamine 6-phosphate. The crystal structure of NtdA shows that NtdA shares the common aspartate aminotransferase fold (Type 1) with residues from both monomers forming the active site. The crystal structures of NtdA alone, co-crystallized with the product ?-D-kanosamine 6-phosphate, and incubated with the amine donor glutamate reveal three key structures in the mechanistic pathway of NtdA. The structure of NtdA alone reveals the internal aldimine form of NtdA with the cofactor pyridoxal phosphate covalently attached to Lys-247. The addition of glutamate results in formation of pyridoxamine phosphate. Co-crystallization with kanosamine 6-phosphate results in the formation of the external aldimine. Only ?-D-kanosamine 6-phosphate is observed in the active site of NtdA, not the ?-anomer. A comparison of the structure and sequence of NtdA with other sugar aminotransferases enables us to propose that the VI? family of aminotransferases should be divided into subfamilies based on the catalytic lysine motif.

SUBMITTER: van Straaten KE

PROVIDER: S-EPMC3837154 | biostudies-literature | 2013 Nov

REPOSITORIES: biostudies-literature

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The structure of NtdA, a sugar aminotransferase involved in the kanosamine biosynthetic pathway in Bacillus subtilis, reveals a new subclass of aminotransferases.

van Straaten Karin E KE Ko Jong Bum JB Jagdhane Rajendra R Anjum Shazia S Palmer David R J DRJ Sanders David A R DAR

The Journal of biological chemistry 20131004 47

NtdA from Bacillus subtilis is a sugar aminotransferase that catalyzes the pyridoxal phosphate-dependent equatorial transamination of 3-oxo-α-D-glucose 6-phosphate to form α-D-kanosamine 6-phosphate. The crystal structure of NtdA shows that NtdA shares the common aspartate aminotransferase fold (Type 1) with residues from both monomers forming the active site. The crystal structures of NtdA alone, co-crystallized with the product α-D-kanosamine 6-phosphate, and incubated with the amine donor glu ...[more]

PMID: 24097983

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Dataset Information

The structure of NtdA, a sugar aminotransferase involved in the kanosamine biosynthetic pathway in Bacillus subtilis, reveals a new subclass of aminotransferases.

Publications

The structure of NtdA, a sugar aminotransferase involved in the kanosamine biosynthetic pathway in Bacillus subtilis, reveals a new subclass of aminotransferases.

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