Amino acid dipepetide frequency for Escherichia coli (strain K12)

Apart from single amino acid frequencies one can also calculate so called amino acid dipeptide frequency.

There is 400 possibilites (441 if we consider Xaa as additional 21st amino acid representing all non-standard or unknown amino acids). Thus, if the dipeptides would be present randomly in proteins each amino acid dipeptide should be present with 0.25% frequency. As it is not the case in the nature, for better visablity all more than expected dipepetides are marked by red, and those which are underrepresented are marked by blue in the table.

All values are presented as per milles (‰), therefore need to be multiplied by 10^-3.

For more information see sequence space article on Wikipedia.

	Ala	Cys	Asp	Glu	Phe	Gly	His	Ile	Lys	Leu	Met	Asn	Pro	Gln	Arg	Ser	Thr	Val	Trp	Tyr	Xaa
Ala	9.616AlaAla: 9.616 ± 0.109	1.154AlaCys: 1.154 ± 0.031	4.937AlaAsp: 4.937 ± 0.06	5.799AlaGlu: 5.799 ± 0.078	3.536AlaPhe: 3.536 ± 0.05	7.231AlaGly: 7.231 ± 0.078	1.873AlaHis: 1.873 ± 0.04	5.964AlaIle: 5.964 ± 0.067	4.12AlaLys: 4.12 ± 0.066	11.178AlaLeu: 11.178 ± 0.092	2.999AlaMet: 2.999 ± 0.049	3.226AlaAsn: 3.226 ± 0.053	3.512AlaPro: 3.512 ± 0.057	4.354AlaGln: 4.354 ± 0.069	5.298AlaArg: 5.298 ± 0.07	5.259AlaSer: 5.259 ± 0.071	4.783AlaThr: 4.783 ± 0.066	6.645AlaVal: 6.645 ± 0.075	1.6AlaTrp: 1.6 ± 0.036	1.943AlaTyr: 1.943 ± 0.037	0.001AlaXaa: 0.001 ± 0.001
Cys	1.036CysAla: 1.036 ± 0.026	0.215CysCys: 0.215 ± 0.014	0.638CysAsp: 0.638 ± 0.022	0.669CysGlu: 0.669 ± 0.025	0.467CysPhe: 0.467 ± 0.019	1.111CysGly: 1.111 ± 0.027	0.348CysHis: 0.348 ± 0.018	0.64CysIle: 0.64 ± 0.023	0.359CysLys: 0.359 ± 0.017	1.084CysLeu: 1.084 ± 0.029	0.254CysMet: 0.254 ± 0.015	0.367CysAsn: 0.367 ± 0.017	0.576CysPro: 0.576 ± 0.019	0.504CysGln: 0.504 ± 0.02	0.67CysArg: 0.67 ± 0.022	0.758CysSer: 0.758 ± 0.022	0.541CysThr: 0.541 ± 0.021	0.801CysVal: 0.801 ± 0.025	0.204CysTrp: 0.204 ± 0.011	0.377CysTyr: 0.377 ± 0.016	0.0CysXaa: 0.0 ± 0.0
Asp	5.015AspAla: 5.015 ± 0.067	0.553AspCys: 0.553 ± 0.022	2.92AspAsp: 2.92 ± 0.054	3.575AspGlu: 3.575 ± 0.06	2.076AspPhe: 2.076 ± 0.038	3.733AspGly: 3.733 ± 0.055	0.995AspHis: 0.995 ± 0.027	3.514AspIle: 3.514 ± 0.047	2.639AspLys: 2.639 ± 0.048	4.632AspLeu: 4.632 ± 0.061	1.287AspMet: 1.287 ± 0.032	2.316AspAsn: 2.316 ± 0.044	2.211AspPro: 2.211 ± 0.045	1.646AspGln: 1.646 ± 0.035	2.525AspArg: 2.525 ± 0.052	2.765AspSer: 2.765 ± 0.046	2.519AspThr: 2.519 ± 0.052	3.804AspVal: 3.804 ± 0.055	0.819AspTrp: 0.819 ± 0.027	1.929AspTyr: 1.929 ± 0.039	0.0AspXaa: 0.0 ± 0.0
Glu	5.183GluAla: 5.183 ± 0.066	0.536GluCys: 0.536 ± 0.018	2.439GluAsp: 2.439 ± 0.048	3.697GluGlu: 3.697 ± 0.071	1.87GluPhe: 1.87 ± 0.036	3.629GluGly: 3.629 ± 0.05	1.446GluHis: 1.446 ± 0.033	3.541GluIle: 3.541 ± 0.05	3.448GluLys: 3.448 ± 0.047	6.096GluLeu: 6.096 ± 0.08	1.905GluMet: 1.905 ± 0.041	2.573GluAsn: 2.573 ± 0.041	2.067GluPro: 2.067 ± 0.043	3.478GluGln: 3.478 ± 0.055	3.598GluArg: 3.598 ± 0.059	3.004GluSer: 3.004 ± 0.047	2.954GluThr: 2.954 ± 0.044	3.821GluVal: 3.821 ± 0.061	0.827GluTrp: 0.827 ± 0.024	1.589GluTyr: 1.589 ± 0.043	0.001GluXaa: 0.001 ± 0.001
Phe	3.777PheAla: 3.777 ± 0.06	0.569PheCys: 0.569 ± 0.02	2.313PheAsp: 2.313 ± 0.043	1.767PheGlu: 1.767 ± 0.037	1.714PhePhe: 1.714 ± 0.048	3.185PheGly: 3.185 ± 0.056	0.822PheHis: 0.822 ± 0.023	2.62PheIle: 2.62 ± 0.049	1.37PheLys: 1.37 ± 0.034	3.36PheLeu: 3.36 ± 0.055	1.03PheMet: 1.03 ± 0.032	1.817PheAsn: 1.817 ± 0.035	1.552PhePro: 1.552 ± 0.033	1.037PheGln: 1.037 ± 0.029	1.873PheArg: 1.873 ± 0.033	3.135PheSer: 3.135 ± 0.052	2.484PheThr: 2.484 ± 0.043	2.57PheVal: 2.57 ± 0.044	0.645PheTrp: 0.645 ± 0.022	1.231PheTyr: 1.231 ± 0.028	0.001PheXaa: 0.001 ± 0.001
Gly	6.125GlyAla: 6.125 ± 0.076	1.07GlyCys: 1.07 ± 0.032	3.664GlyAsp: 3.664 ± 0.049	4.596GlyGlu: 4.596 ± 0.063	3.259GlyPhe: 3.259 ± 0.056	5.392GlyGly: 5.392 ± 0.084	1.628GlyHis: 1.628 ± 0.038	5.12GlyIle: 5.12 ± 0.064	4.146GlyLys: 4.146 ± 0.058	7.316GlyLeu: 7.316 ± 0.083	2.411GlyMet: 2.411 ± 0.045	2.896GlyAsn: 2.896 ± 0.052	1.997GlyPro: 1.997 ± 0.04	2.755GlyGln: 2.755 ± 0.05	3.642GlyArg: 3.642 ± 0.065	4.015GlySer: 4.015 ± 0.058	3.748GlyThr: 3.748 ± 0.06	5.879GlyVal: 5.879 ± 0.062	1.285GlyTrp: 1.285 ± 0.035	2.654GlyTyr: 2.654 ± 0.051	0.001GlyXaa: 0.001 ± 0.001
His	1.869HisAla: 1.869 ± 0.034	0.36HisCys: 0.36 ± 0.017	1.169HisAsp: 1.169 ± 0.027	1.154HisGlu: 1.154 ± 0.029	1.036HisPhe: 1.036 ± 0.028	1.725HisGly: 1.725 ± 0.037	0.742HisHis: 0.742 ± 0.026	1.385HisIle: 1.385 ± 0.03	0.8HisLys: 0.8 ± 0.027	2.222HisLeu: 2.222 ± 0.046	0.575HisMet: 0.575 ± 0.021	0.903HisAsn: 0.903 ± 0.023	1.336HisPro: 1.336 ± 0.033	1.163HisGln: 1.163 ± 0.033	1.234HisArg: 1.234 ± 0.03	1.259HisSer: 1.259 ± 0.031	1.063HisThr: 1.063 ± 0.022	1.345HisVal: 1.345 ± 0.031	0.403HisTrp: 0.403 ± 0.018	0.923HisTyr: 0.923 ± 0.024	0.0HisXaa: 0.0 ± 0.0
Ile	6.588IleAla: 6.588 ± 0.079	0.778IleCys: 0.778 ± 0.028	3.573IleAsp: 3.573 ± 0.053	3.35IleGlu: 3.35 ± 0.053	2.247IlePhe: 2.247 ± 0.045	4.713IleGly: 4.713 ± 0.068	1.237IleHis: 1.237 ± 0.027	3.687IleIle: 3.687 ± 0.063	2.546IleLys: 2.546 ± 0.051	5.157IleLeu: 5.157 ± 0.071	1.405IleMet: 1.405 ± 0.034	2.885IleAsn: 2.885 ± 0.053	2.926IlePro: 2.926 ± 0.043	1.88IleGln: 1.88 ± 0.038	3.053IleArg: 3.053 ± 0.05	4.025IleSer: 4.025 ± 0.056	3.633IleThr: 3.633 ± 0.056	4.101IleVal: 4.101 ± 0.06	0.709IleTrp: 0.709 ± 0.024	1.614IleTyr: 1.614 ± 0.039	0.0IleXaa: 0.0 ± 0.0
Lys	4.346LysAla: 4.346 ± 0.062	0.34LysCys: 0.34 ± 0.017	2.154LysAsp: 2.154 ± 0.044	2.72LysGlu: 2.72 ± 0.047	1.245LysPhe: 1.245 ± 0.033	3.017LysGly: 3.017 ± 0.052	0.915LysHis: 0.915 ± 0.026	2.575LysIle: 2.575 ± 0.045	2.333LysLys: 2.333 ± 0.05	4.483LysLeu: 4.483 ± 0.058	1.39LysMet: 1.39 ± 0.033	1.937LysAsn: 1.937 ± 0.036	2.237LysPro: 2.237 ± 0.044	2.068LysGln: 2.068 ± 0.04	2.624LysArg: 2.624 ± 0.042	2.355LysSer: 2.355 ± 0.043	2.653LysThr: 2.653 ± 0.043	3.086LysVal: 3.086 ± 0.053	0.477LysTrp: 0.477 ± 0.018	1.185LysTyr: 1.185 ± 0.03	0.0LysXaa: 0.0 ± 0.0
Leu	11.172LeuAla: 11.172 ± 0.102	1.334LeuCys: 1.334 ± 0.035	5.223LeuAsp: 5.223 ± 0.068	5.542LeuGlu: 5.542 ± 0.073	4.243LeuPhe: 4.243 ± 0.065	7.086LeuGly: 7.086 ± 0.072	2.26LeuHis: 2.26 ± 0.043	5.986LeuIle: 5.986 ± 0.077	4.653LeuLys: 4.653 ± 0.067	11.69LeuLeu: 11.69 ± 0.126	3.017LeuMet: 3.017 ± 0.047	4.42LeuAsn: 4.42 ± 0.059	5.653LeuPro: 5.653 ± 0.071	4.129LeuGln: 4.129 ± 0.062	6.023LeuArg: 6.023 ± 0.07	6.815LeuSer: 6.815 ± 0.069	6.363LeuThr: 6.363 ± 0.073	7.087LeuVal: 7.087 ± 0.084	1.449LeuTrp: 1.449 ± 0.031	2.568LeuTyr: 2.568 ± 0.05	0.0LeuXaa: 0.0 ± 0.0
Met	2.878MetAla: 2.878 ± 0.043	0.234MetCys: 0.234 ± 0.012	1.224MetAsp: 1.224 ± 0.029	1.307MetGlu: 1.307 ± 0.03	0.935MetPhe: 0.935 ± 0.026	1.958MetGly: 1.958 ± 0.043	0.527MetHis: 0.527 ± 0.02	1.611MetIle: 1.611 ± 0.037	1.456MetLys: 1.456 ± 0.03	3.25MetLeu: 3.25 ± 0.057	0.968MetMet: 0.968 ± 0.032	1.181MetAsn: 1.181 ± 0.031	1.382MetPro: 1.382 ± 0.031	1.26MetGln: 1.26 ± 0.032	1.512MetArg: 1.512 ± 0.032	1.928MetSer: 1.928 ± 0.035	1.868MetThr: 1.868 ± 0.034	1.967MetVal: 1.967 ± 0.039	0.277MetTrp: 0.277 ± 0.015	0.561MetTyr: 0.561 ± 0.02	0.001MetXaa: 0.001 ± 0.001
Asn	3.656AsnAla: 3.656 ± 0.057	0.413AsnCys: 0.413 ± 0.016	2.124AsnAsp: 2.124 ± 0.042	2.108AsnGlu: 2.108 ± 0.038	1.434AsnPhe: 1.434 ± 0.035	3.295AsnGly: 3.295 ± 0.073	0.873AsnHis: 0.873 ± 0.026	2.57AsnIle: 2.57 ± 0.042	1.76AsnLys: 1.76 ± 0.038	3.67AsnLeu: 3.67 ± 0.051	1.023AsnMet: 1.023 ± 0.029	1.815AsnAsn: 1.815 ± 0.045	2.161AsnPro: 2.161 ± 0.042	1.691AsnGln: 1.691 ± 0.038	2.046AsnArg: 2.046 ± 0.037	2.115AsnSer: 2.115 ± 0.047	2.054AsnThr: 2.054 ± 0.049	2.701AsnVal: 2.701 ± 0.043	0.628AsnTrp: 0.628 ± 0.022	1.278AsnTyr: 1.278 ± 0.037	0.0AsnXaa: 0.0 ± 0.0
Pro	4.209ProAla: 4.209 ± 0.069	0.41ProCys: 0.41 ± 0.017	2.716ProAsp: 2.716 ± 0.048	3.438ProGlu: 3.438 ± 0.049	1.876ProPhe: 1.876 ± 0.037	3.507ProGly: 3.507 ± 0.045	1.046ProHis: 1.046 ± 0.029	1.946ProIle: 1.946 ± 0.042	1.575ProLys: 1.575 ± 0.041	5.105ProLeu: 5.105 ± 0.057	1.105ProMet: 1.105 ± 0.029	1.286ProAsn: 1.286 ± 0.033	1.636ProPro: 1.636 ± 0.041	2.351ProGln: 2.351 ± 0.048	1.986ProArg: 1.986 ± 0.046	2.148ProSer: 2.148 ± 0.037	2.104ProThr: 2.104 ± 0.042	3.89ProVal: 3.89 ± 0.06	0.752ProTrp: 0.752 ± 0.023	1.198ProTyr: 1.198 ± 0.029	0.0ProXaa: 0.0 ± 0.0
Gln	4.401GlnAla: 4.401 ± 0.069	0.387GlnCys: 0.387 ± 0.018	1.743GlnAsp: 1.743 ± 0.041	2.291GlnGlu: 2.291 ± 0.043	1.543GlnPhe: 1.543 ± 0.032	2.974GlnGly: 2.974 ± 0.056	1.275GlnHis: 1.275 ± 0.031	2.355GlnIle: 2.355 ± 0.052	1.916GlnLys: 1.916 ± 0.04	5.008GlnLeu: 5.008 ± 0.069	1.253GlnMet: 1.253 ± 0.03	1.57GlnAsn: 1.57 ± 0.039	2.178GlnPro: 2.178 ± 0.048	3.28GlnGln: 3.28 ± 0.077	2.931GlnArg: 2.931 ± 0.053	2.295GlnSer: 2.295 ± 0.044	2.206GlnThr: 2.206 ± 0.041	2.872GlnVal: 2.872 ± 0.048	0.742GlnTrp: 0.742 ± 0.023	1.245GlnTyr: 1.245 ± 0.033	0.0GlnXaa: 0.0 ± 0.0
Arg	4.376ArgAla: 4.376 ± 0.054	0.612ArgCys: 0.612 ± 0.02	2.983ArgAsp: 2.983 ± 0.046	3.793ArgGlu: 3.793 ± 0.058	2.461ArgPhe: 2.461 ± 0.042	3.315ArgGly: 3.315 ± 0.049	1.551ArgHis: 1.551 ± 0.035	3.344ArgIle: 3.344 ± 0.046	2.505ArgLys: 2.505 ± 0.044	6.111ArgLeu: 6.111 ± 0.093	1.575ArgMet: 1.575 ± 0.033	2.119ArgAsn: 2.119 ± 0.036	2.1ArgPro: 2.1 ± 0.043	2.954ArgGln: 2.954 ± 0.056	3.479ArgArg: 3.479 ± 0.061	2.715ArgSer: 2.715 ± 0.048	2.502ArgThr: 2.502 ± 0.044	3.743ArgVal: 3.743 ± 0.058	0.947ArgTrp: 0.947 ± 0.026	2.139ArgTyr: 2.139 ± 0.046	0.0ArgXaa: 0.0 ± 0.0
Ser	5.314SerAla: 5.314 ± 0.084	0.649SerCys: 0.649 ± 0.023	2.996SerAsp: 2.996 ± 0.051	3.224SerGlu: 3.224 ± 0.05	2.277SerPhe: 2.277 ± 0.042	5.202SerGly: 5.202 ± 0.072	1.408SerHis: 1.408 ± 0.034	3.058SerIle: 3.058 ± 0.052	2.106SerLys: 2.106 ± 0.038	6.611SerLeu: 6.611 ± 0.073	1.538SerMet: 1.538 ± 0.033	1.98SerAsn: 1.98 ± 0.046	2.553SerPro: 2.553 ± 0.043	2.52SerGln: 2.52 ± 0.049	3.392SerArg: 3.392 ± 0.052	3.457SerSer: 3.457 ± 0.067	3.001SerThr: 3.001 ± 0.058	4.129SerVal: 4.129 ± 0.062	0.973SerTrp: 0.973 ± 0.028	1.615SerTyr: 1.615 ± 0.039	0.0SerXaa: 0.0 ± 0.0
Thr	5.049ThrAla: 5.049 ± 0.071	0.557ThrCys: 0.557 ± 0.019	2.663ThrAsp: 2.663 ± 0.042	2.633ThrGlu: 2.633 ± 0.045	2.146ThrPhe: 2.146 ± 0.039	4.512ThrGly: 4.512 ± 0.068	1.253ThrHis: 1.253 ± 0.029	3.124ThrIle: 3.124 ± 0.049	1.578ThrLys: 1.578 ± 0.036	7.208ThrLeu: 7.208 ± 0.089	1.204ThrMet: 1.204 ± 0.029	1.682ThrAsn: 1.682 ± 0.039	3.182ThrPro: 3.182 ± 0.053	2.198ThrGln: 2.198 ± 0.04	2.984ThrArg: 2.984 ± 0.05	2.897ThrSer: 2.897 ± 0.056	3.014ThrThr: 3.014 ± 0.064	3.949ThrVal: 3.949 ± 0.068	0.854ThrTrp: 0.854 ± 0.024	1.201ThrTyr: 1.201 ± 0.03	0.001ThrXaa: 0.001 ± 0.001
Val	6.945ValAla: 6.945 ± 0.068	0.843ValCys: 0.843 ± 0.023	3.775ValAsp: 3.775 ± 0.055	4.11ValGlu: 4.11 ± 0.064	2.582ValPhe: 2.582 ± 0.052	4.852ValGly: 4.852 ± 0.068	1.265ValHis: 1.265 ± 0.029	4.773ValIle: 4.773 ± 0.06	3.255ValLys: 3.255 ± 0.051	7.165ValLeu: 7.165 ± 0.087	2.233ValMet: 2.233 ± 0.046	2.881ValAsn: 2.881 ± 0.054	3.01ValPro: 3.01 ± 0.056	2.329ValGln: 2.329 ± 0.045	3.541ValArg: 3.541 ± 0.052	4.427ValSer: 4.427 ± 0.064	4.281ValThr: 4.281 ± 0.064	5.7ValVal: 5.7 ± 0.074	0.981ValTrp: 0.981 ± 0.026	1.76ValTyr: 1.76 ± 0.034	0.0ValXaa: 0.0 ± 0.0
Trp	1.031TrpAla: 1.031 ± 0.028	0.209TrpCys: 0.209 ± 0.013	0.629TrpAsp: 0.629 ± 0.023	0.592TrpGlu: 0.592 ± 0.024	0.714TrpPhe: 0.714 ± 0.023	0.934TrpGly: 0.934 ± 0.026	0.458TrpHis: 0.458 ± 0.017	0.774TrpIle: 0.774 ± 0.025	0.549TrpLys: 0.549 ± 0.021	2.329TrpLeu: 2.329 ± 0.049	0.477TrpMet: 0.477 ± 0.019	0.491TrpAsn: 0.491 ± 0.02	0.646TrpPro: 0.646 ± 0.021	1.28TrpGln: 1.28 ± 0.033	1.08TrpArg: 1.08 ± 0.028	0.83TrpSer: 0.83 ± 0.029	0.592TrpThr: 0.592 ± 0.023	0.942TrpVal: 0.942 ± 0.028	0.246TrpTrp: 0.246 ± 0.014	0.458TrpTyr: 0.458 ± 0.018	0.001TrpXaa: 0.001 ± 0.001
Tyr	2.441TyrAla: 2.441 ± 0.041	0.395TyrCys: 0.395 ± 0.016	1.589TyrAsp: 1.589 ± 0.044	1.333TyrGlu: 1.333 ± 0.036	1.21TyrPhe: 1.21 ± 0.03	2.225TyrGly: 2.225 ± 0.042	0.747TyrHis: 0.747 ± 0.024	1.52TyrIle: 1.52 ± 0.036	1.025TyrLys: 1.025 ± 0.024	3.039TyrLeu: 3.039 ± 0.048	0.635TyrMet: 0.635 ± 0.022	1.07TyrAsn: 1.07 ± 0.034	1.369TyrPro: 1.369 ± 0.033	1.587TyrGln: 1.587 ± 0.033	1.831TyrArg: 1.831 ± 0.041	1.801TyrSer: 1.801 ± 0.036	1.526TyrThr: 1.526 ± 0.034	1.675TyrVal: 1.675 ± 0.037	0.448TyrTrp: 0.448 ± 0.019	0.985TyrTyr: 0.985 ± 0.026	0.0TyrXaa: 0.0 ± 0.0
Xaa	0.001XaaAla: 0.001 ± 0.001	0.0XaaCys: 0.0 ± 0.0	0.001XaaAsp: 0.001 ± 0.001	0.001XaaGlu: 0.001 ± 0.001	0.0XaaPhe: 0.0 ± 0.0	0.001XaaGly: 0.001 ± 0.001	0.0XaaHis: 0.0 ± 0.0	0.0XaaIle: 0.0 ± 0.0	0.0XaaLys: 0.0 ± 0.0	0.001XaaLeu: 0.001 ± 0.001	0.0XaaMet: 0.0 ± 0.0	0.0XaaAsn: 0.0 ± 0.0	0.0XaaPro: 0.0 ± 0.0	0.001XaaGln: 0.001 ± 0.001	0.0XaaArg: 0.0 ± 0.0	0.001XaaSer: 0.001 ± 0.001	0.0XaaThr: 0.0 ± 0.0	0.0XaaVal: 0.0 ± 0.0	0.0XaaTrp: 0.0 ± 0.0	0.0XaaTyr: 0.0 ± 0.0	0.0XaaXaa: 0.0 ± 0.0

Statistics based on 4450 proteins (1363428 amino acids)

Note: The error has been estimated with the bootstraping (x100) at the protein level

Above dipeptide statistics (among other stats for this proteome) you can download from this CSV file

Reference: Kozlowski LP. Proteome-pI 2.0: Proteome Isoelectric Point Database Update. Nucleic Acids Res. 2021, doi: 10.1093/nar/gkab944

Contact: Lukasz P. Kozlowski

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