4FPW

Crystal Structure of CalU16 from Micromonospora echinospora. Northeast Structural Genomics Consortium Target MiR12.

Summary for 4FPW

• Entry DOI: 10.2210/pdb4fpw/pdb
• Descriptor: CalU16 (2 entities in total)
• Functional Keywords: structural genomics, psi-biology, northeast structural genomics consortium, nesg, calu16, unknown function
• Biological source: Micromonospora echinospora
• Total number of polymer chains: 2
• Total formula weight: 40471.46

Authors

Seetharaman, J.,Lew, S.,Janjua, H.,Xiao, R.,Acton, T.B.,Everett, J.K.,Phillips Jr., G.N.,Kennedy, M.A.,Montelione, G.T.,Hunt, J.F.,Tong, L.,Northeast Structural Genomics Consortium (NESG) (deposition date: 2012-06-22, release date: 2012-12-12, Last modification date: 2024-10-16)

Primary citation

Elshahawi, S.I.,Ramelot, T.A.,Seetharaman, J.,Chen, J.,Singh, S.,Yang, Y.,Pederson, K.,Kharel, M.K.,Xiao, R.,Lew, S.,Yennamalli, R.M.,Miller, M.D.,Wang, F.,Tong, L.,Montelione, G.T.,Kennedy, M.A.,Bingman, C.A.,Zhu, H.,Phillips, G.N.,Thorson, J.S.
Structure-Guided Functional Characterization of Enediyne Self-Sacrifice Resistance Proteins, CalU16 and CalU19.
Acs Chem.Biol., 9:2347-2358, 2014

PubMed Abstract: Calicheamicin γ1I (1) is an enediyne antitumor compound produced by Micromonospora echinospora spp. calichensis, and its biosynthetic gene cluster has been previously reported. Despite extensive analysis and biochemical study, several genes in the biosynthetic gene cluster of 1 remain functionally unassigned. Using a structural genomics approach and biochemical characterization, two proteins encoded by genes from the 1 biosynthetic gene cluster assigned as "unknowns", CalU16 and CalU19, were characterized. Structure analysis revealed that they possess the STeroidogenic Acute Regulatory protein related lipid Transfer (START) domain known mainly to bind and transport lipids and previously identified as the structural signature of the enediyne self-resistance protein CalC. Subsequent study revealed calU16 and calU19 to confer resistance to 1, and reminiscent of the prototype CalC, both CalU16 and CalU19 were cleaved by 1 in vitro. Through site-directed mutagenesis and mass spectrometry, we identified the site of cleavage in each protein and characterized their function in conferring resistance against 1. This report emphasizes the importance of structural genomics as a powerful tool for the functional annotation of unknown proteins.

PubMed: 25079510
DOI: 10.1021/cb500327m

Experimental method

X-RAY DIFFRACTION (2.5 Å)