SASDDK2: Aspergillus fumigatus UDP galactopyranose mutase

Basic information

• Entry: Database: SASBDB / ID: SASDDK2

Sample

Aspergillus fumigatus UDP galactopyranose mutase

• Aspergillus fumigatus UDP galactopyranose mutase (protein)

• Citation: Journal: J Biol Chem / Year: 2012; Title: Crystal structures and small-angle x-ray scattering analysis of UDP-galactopyranose mutase from the pathogenic fungus Aspergillus fumigatus.; Authors: Richa Dhatwalia / Harkewal Singh / Michelle Oppenheimer / Dale B Karr / Jay C Nix / Pablo Sobrado / John J Tanner / ; Abstract: UDP-galactopyranose mutase (UGM) is a flavoenzyme that catalyzes the conversion of UDP-galactopyranose to UDP-galactofuranose, which is a central reaction in galactofuranose biosynthesis. Galactofuranose has never been found in humans but is an essential building block of the cell wall and extracellular matrix of many bacteria, fungi, and protozoa. The importance of UGM for the viability of many pathogens and its absence in humans make UGM a potential drug target. Here we report the first crystal structures and small-angle x-ray scattering data for UGM from the fungus Aspergillus fumigatus, the causative agent of aspergillosis. The structures reveal that Aspergillus UGM has several extra secondary and tertiary structural elements that are not found in bacterial UGMs yet are important for substrate recognition and oligomerization. Small-angle x-ray scattering data show that Aspergillus UGM forms a tetramer in solution, which is unprecedented for UGMs. The binding of UDP or the substrate induces profound conformational changes in the enzyme. Two loops on opposite sides of the active site move toward each other by over 10 Å to cover the substrate and create a closed active site. The degree of substrate-induced conformational change exceeds that of bacterial UGMs and is a direct consequence of the unique quaternary structure of Aspergillus UGM. Galactopyranose binds at the re face of the FAD isoalloxazine with the anomeric carbon atom poised for nucleophilic attack by the FAD N5 atom. The structural data provide new insight into substrate recognition and the catalytic mechanism and thus will aid inhibitor design.

Contact author

• John Tanner (Mizzou, University of Missouri-Columbia, Columbia, MO, USA)

Models

• Model #1716: ; Type: atomic / Radius of dummy atoms: 1.90 A / Chi-square value: 12.0390640394; Search similar-shape structures of this assembly by Omokage search (details)

Sample

• Sample: Name: Aspergillus fumigatus UDP galactopyranose mutase / Specimen concentration: 9 mg/ml
• Buffer: Name: 20 mM HEPES, 45 mM NaCl, 0.5 mM Tris(hydroxypropyl)phosphine; pH: 7.5

Entity #930

Type: protein
Description: Aspergillus fumigatus UDP galactopyranose mutase
Formula weight: 57.068 / Num. of mol.: 4
Sequence:

AIAMTHPDIS VDVLVIGAGP TGLGAAKRLN QIDGPSWMIV DSNETPGGLA STDVTPEGFL YDVGGHVIFS HYKYFDDCLD EALPKEDDWY THQRISYVRC QGQWVPYPFQ NNISMLPKEE QVKCIDGMID AALEARVANT KPKTFDEWIV RMMGTGIADL FMRPYNFKVW AVPTTKMQCA WLGERVAAPN LKAVTTNVIL GKTAGNWGPN ATFRFPARGG TGGIWIAVAN TLPKEKTRFG EKGKVTKVNA NNKTVTLQDG TTIGYKKLVS TMAVDFLAEA MNDQELVGLT KQLFYSSTHV IGVGVRGSRP ERIGDKCWLY FPEDNCPFYR ATIFSNYSPY NQPEASAALP TMQLADGSRP QSTEAKEGPY WSIMLEVSES SMKPVNQETI LADCIQGLVN TEMLKPTDEI VSTYHRRFDH GYPTPTLERE GTLTQILPKL QDKDIWSRGR FGSWRYEVGN QDHSFMLGVE AVDNIVNGAV ELTLNYPDFV NGRQNTERRL VDGAQVFAKS KAQ

Experimental information

• Beam: Instrument name: Advanced Light Source (ALS) 12.3.1 (SIBYLS); City: Berkeley, CA / 国: USA / Type of source: X-ray synchrotronSynchrotron / Wavelength: 0.1127 Å
• Detector: Name: MAR 165 CCD

Scan

Title: Aspergillus fumigatus UDP galactopyranose mutase / Measurement date: Apr 19, 2010 / Cell temperature: 10 °C / Unit: 1/A /

	Min	Max
Q	0.0106	0.3213

Distance distribution function P(R)

Sofotware P(R): GNOM 5.0 / Number of points: 512 /

	Min	Max
Q	0.010641	0.321334
P(R) point	1	512
R	0	146.8

Result

Type of curve: single_conc /

	Experimental	Porod
MW	228.3 kDa	-
Volume	-	308 nm3

	P(R)	P(R) error	Guinier	Guinier error
Forward scattering, I0	893.5	1	892.91	1.7
Radius of gyration, Rg	4.77 nm	-	4.727 nm	0.013

	Min	Max
D	-	14.68
Guinier point	1	28