6.2.1.45	A189T	improved stability and activity compared to mutant A189T/W714C, but when incubated at 39°C, cells expressing the mutant show increased apoptotic rate ompared to wild-type. Mutant is able to monoubiquitinate histone H2A and to support growth of TS20 cells at 39°C. Compared to mutant A189T/W714C, mutation A189T significantly improves the ubiquitination-dependent disposal of HIF-1alpha	728028	
6.2.1.45	A189T	the mutant enzyme is less stable than its wild-type counterpart, and restrictive temperature (39°C) accelerates its degradation	715718	
6.2.1.45	A189T/W714C	mutant protein is less stable than its wildtype counterpart, and restrictive temperature of 39°C accelerates its degradation	728028	
6.2.1.45	C632A	generation of an active site cysteine mutant of HA-UBE1	735013	
6.2.1.45	D290K/C250A	in this heterodimer, the UBA5 subunit that can form the thioester bond with UFM1 is missing the UFC1 binding site. In the UBA5 (D290K)-UBA5 (K271D/C250A DELTADUIS) heterodimer, binding to the UIS and charging can only take place on the same monomer, thereby supporting a cis-binding mechanism	744655	
6.2.1.45	D576A	Km-value for ATP is 37.8fold higher than wild-type value, KM-value for ubiquitin is 36fold higher than wild-type value. kcat for ubiquitin adenylate formation is 250fold lower than wild-type value. kcat for ubiquitin carrier protein E2 transthiolation is 28.3fold lower than wild-type value	674561	
6.2.1.45	D576A	mutation within the MgATP2- binding site, results in dramatically impaired binding affinities for MgATP2-, a shift from ordered to random addition in co-substrate binding, and a significantly reduced rate of ternary complex formation that shifts the rate-limiting step to ubiquitin adenylate formation. Mutations does not affect the affinity of Ubc2b binding, however, differences in kcat values determined from ternary complex formation versus HsUbc2b transthiolation suggest that binding of the E2 enhances the rate of bound ubiquitin adenylate formation	674561	
6.2.1.45	D576E	Km-value for ATP is 4fold higher than wild-type value, KM-value for ubiquitin is 1.4fold higher than wild-type value. kcat for ubiquitin adenylate formation is 1200fold lower than wild-type value. kcat for ubiquitin carrier protein E2 transthiolation is 34fold lower than wild-type value	674561	
6.2.1.45	D576E	mutation within the MgATP2- binding site, results in dramatically impaired binding affinities for MgATP2-, a shift from ordered to random addition in co-substrate binding, and a significantly reduced rate of ternary complex formation that shifts the rate-limiting step to ubiquitin adenylate formation. Mutations does not affect the affinity of Ubc2b binding, however, differences in kcat values determined from ternary complex formation versus HsUbc2b transthiolation suggest that binding of the E2 enhances the rate of bound ubiquitin adenylate formation	674561	
6.2.1.45	D576N	Km-value for ATP is 5.2fold higher than wild-type value, KM-value for ubiquitin is 5fold higher than wild-type value. kcat for ubiquitin adenylate formation is 545fold lower than wild-type value. kcat for ubiquitin carrier protein E2 transthiolation is 155fold lower than wild-type value	674561	
6.2.1.45	D576N	mutation within the MgATP2- binding site, results in dramatically impaired binding affinities for MgATP2-, a shift from ordered to random addition in co-substrate binding, and a significantly reduced rate of ternary complex formation that shifts the rate-limiting step to ubiquitin adenylate formation. Mutations does not affect the affinity of Ubc2b binding, however, differences in kcat values determined from ternary complex formation versus HsUbc2b transthiolation suggest that binding of the E2 enhances the rate of bound ubiquitin adenylate formation	674561	
6.2.1.45	D616R	site-directed mutagenesis	745863	
6.2.1.45	D623R	site-directed mutagenesis	745863	
6.2.1.45	E601R	site-directed mutagenesis	745863	
6.2.1.45	H614R	site-directed mutagenesis	745863	
6.2.1.45	K528A	Km-value for ATP is 1.6fold higher than wild-type value, KM-value for ubiquitin is 2.9fold higher than wild-type value. kcat for ubiquitin adenylate formation is 400fold lower than wild-type value. kcat for ubiquitin carrier protein E2 transthiolation is 309fold lower than wild-type value	674561	
6.2.1.45	K528A	mutation within the MgATP2- binding site, results in dramatically impaired binding affinities for MgATP2-, a shift from ordered to random addition in co-substrate binding, and a significantly reduced rate of ternary complex formation that shifts the rate-limiting step to ubiquitin adenylate formation. Mutations does not affect the affinity of Ubc2b binding, however, differences in kcat values determined from ternary complex formation versus HsUbc2b transthiolation suggest that binding of the E2 enhances the rate of bound ubiquitin adenylate formation	674561	
6.2.1.45	additional information	a mutational reduction in Uba1 function (Uba1B2 mutation) reduces the efficacy of cell death, a complete loss of Uba1 function (Uba1A1 mutation) results in poor survival of mutant tissue and overgrowth of adjacent wild type tissue	692413	
6.2.1.45	additional information	construction of a mouse Aos1-Uba2 chimeric SUMO(small ubiquitin-related modifier)-E1 enzyme, mAU. The SUMO-E1 enzyme consists of two subunits, a heterodimer of activation of Smt3p 1 (Aos1) and ubiquitin activating enzyme 2 (Uba2), which resembles the N- and C-terminal halves of ubiquitin E1 (Uba1), the functional domains appear to be arranged in a fashion similar to Uba1. mAU has SUMO-E1 activity, indicating that mAU can be expressed in baculovirus-insect cells and represents a suitable source of SUMO-E1, enzymatic mechanism and structure of SUMO-E1, overview	733442	
6.2.1.45	additional information	enzyme silencing in HEK293 cells by lentiviral expression of shRNA. Generation of orthogonal pairs of xUB-xUBA6 and xUB-xUBA1, analysis of orthogonal interaction of xUB-xE1 in mammalian cells and identification of xUB-conjugated proteins. 697 potential Uba6 targets and 527 potential Uba1 targets with 258 overlaps are identified	745863	
6.2.1.45	additional information	genotyping-phenotyping	735079	
6.2.1.45	additional information	isolation of a mutant in ubiquitin-activiting enzyme Uba1. The mutation alters sensitivity to various environmental stresses and reduces wild-type Uba1 protein function. Protein modification by ubiquitin is strongly impaired in the mutant, inhibiting degradation of ubiquitin-proteasome pathway substrates as well as ubiquitin-dependent but proteasome-independent degradation of membrane receptors	727501	
6.2.1.45	additional information	MCF-10A cells stably expressing anti-UBA6 shRNA form similar structures as the wild-type cells, but also develop a number (about 5%) of tumor-like gigantic aggregates, approximately 30% of acini formed in the shUBA6 culture do not exhibit hollow lumen. UBA6 knockout cell phenotype, overview	745952	
6.2.1.45	additional information	mutagenesis of key residues of E1 reveals that its conserved catalytic cysteine residue is essential for the formation of these poyubiquitin chains. Inactivation of the ubiquitin-conjugating enzyme E2 has no effect on the ability of E1 to catalyze ubiquitin chain formation, suggesting E1 is not only responsible for the activaton of ubiquitin but also for the direct extension of the lysine 48-linked polyubiquitin chain by the direct transfer of the ubiquitin-thiolester from the active site of E1 to the terminal Lys48 of the growing chain	725376	
6.2.1.45	additional information	only full-length GSTHsUba1a is catalytically active	674561	
6.2.1.45	additional information	reduced survival rates of Saccharomyces cerevisiae strain MHY501 expressing the domains of ubiquitin-activating enzyme E1 under heat stress with or without inducer CuSO4, overview. Under antibiotic and heat stresses expression of the domains SCCH and UFD prove to be detrimental to cell survival	-, 760825	
6.2.1.45	additional information	removal of residues 330-404 of the C-terminal domain does not abrogate formation of the UBA5-ubiquitin fold modifier1 thioester intermediate, the UBA5 C-terminal domain is not required for adenylation or thioester transfer of ubiquitin fold modifier1 to the UBA5 catalytic cysteine	709113	
6.2.1.45	additional information	RNA antisense silencing of Giardia E1. Overexpression of E1 greatly increases the encystation rate	-, 733043	
6.2.1.45	Q608R	site-directed mutagenesis	745863	
6.2.1.45	S621R	site-directed mutagenesis	745863	
6.2.1.45	W714C	the mutant enzyme is less stable than its wild-type counterpart, and restrictive temperature (39°C) accelerates its degradation	715718