Table 1.

Identified autophosphorylation sites of Flag-BRI1 expressed in E. coli.

Site	Counts	Mr (expt)	Mr (calc)	Expect	Peptides
T846	1	1027.1528	1027.4124	1.70E−03	R.TANNpTNWK.L
T846T851*	2	1605.2660	1605.6953	1.40E−04	R.TANNpTNWKLpTGVK.E
S858	283	1750.4736	1750.9018	1.70E−10	K.EALpSINLAAFEKPLR.K
S906*	17	967.2228	967.4739	3.90E−06	K.DGpSAVAIKK.L
S917*	26	1160.2466	1160.5339	1.40E−02	K.LIHVpSGQGDR.E
T930*	6	1364.1704	1364.5393	1.30E−04	R.EFMAEMEpTIGK.I
S963*	95	1451.3046	1451.6334	1.50E−05	K.YGpSLEDVLHDPK.K
S981T982*	6	935.0902	935.3303	3.60E−01	K.LNWpSpTR.R
S990*	2	894.2446	894.4688	1.90E−03	R.KIAIGpSAR.G
S1012*	7	1538.3170	1538.6977	1.50E−05	K.pSSNVLLDENLEAR.V
S1012 or S1013	255	1538.2560	1538.6977	1.40E−08	K.SSNVLLDENLEAR.V
S1012 and S1013*	55	1992.3800	1992.8264	4.50E−12	R.DMKpSpSNVLLDENLEAR.V
S1026*	26	961.1178	961.3729	6.50E−04	R.VpSDFGMAR.L
S1026	4	977.0876	977.3678	4.20E−03	R.VpSDFG(ox)MAR.L
S1109*	4	1641.3456	1641.7837	1.00E−05	K.LRIpSDVFDPELMK.E
S1109	2	1657.3358	1657.7786	4.60E−03	K.LRIpSDVFDPEL(ox)MK.E
T1147*	1	1517.2816	1517.6958	2.10E−04	R.RPpTMVQVMAMFK.E
T1147	6	1533.2764	1533.6907	2.60E−03	R.RPpTMVQVMA(ox)MFK.E
S1166	3	1640.2968	1640.7407	5.20E−08	K.EIQAGSGIDpSQSTIR.S
T1169*	2	1640.2942	1640.7407	2.60E−08	K.EIQAGSGIDSQSpTIR.S
S1166T1169	61	1720.2422	1720.7070	7.40E−09	K.EIQAGSGIDpSQSpTIR.S
S1168T1169	247	1720.2186	1720.7070	5.50E−09	K.EIQAGSGIDSQpSpTIR.S

Tryptic peptides identified to contain phosphorylated residues (pS or pT) are shown in bold and sites not reported unambiguously earlier are identified with asterisks. All spectra were subject to manual verification. The experimental (expt) and calculated (calc) monisotopic masses are shown along with the expectation value (Expect) reported in Mascot. The values for spectral counts for each identified peptide are the sums from three independent experiments. Oxidized methionine is identified as (ox)Met.