Amino acid dipepetide frequency for Helobdella robusta (Californian leech)

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	4.135AlaAla: 4.135 ± 0.037	1.149AlaCys: 1.149 ± 0.012	2.985AlaAsp: 2.985 ± 0.022	2.805AlaGlu: 2.805 ± 0.021	2.081AlaPhe: 2.081 ± 0.017	2.78AlaGly: 2.78 ± 0.027	1.049AlaHis: 1.049 ± 0.012	3.031AlaIle: 3.031 ± 0.023	3.287AlaLys: 3.287 ± 0.024	4.383AlaLeu: 4.383 ± 0.032	1.166AlaMet: 1.166 ± 0.012	2.962AlaAsn: 2.962 ± 0.021	1.826AlaPro: 1.826 ± 0.02	1.549AlaGln: 1.549 ± 0.015	2.269AlaArg: 2.269 ± 0.017	4.659AlaSer: 4.659 ± 0.029	3.84AlaThr: 3.84 ± 0.031	3.452AlaVal: 3.452 ± 0.021	0.491AlaTrp: 0.491 ± 0.008	1.503AlaTyr: 1.503 ± 0.014	0.0AlaXaa: 0.0 ± 0.0
Cys	0.985CysAla: 0.985 ± 0.014	0.758CysCys: 0.758 ± 0.016	1.278CysAsp: 1.278 ± 0.015	1.109CysGlu: 1.109 ± 0.014	1.099CysPhe: 1.099 ± 0.013	1.352CysGly: 1.352 ± 0.015	0.636CysHis: 0.636 ± 0.011	1.301CysIle: 1.301 ± 0.015	1.461CysLys: 1.461 ± 0.016	2.327CysLeu: 2.327 ± 0.022	0.549CysMet: 0.549 ± 0.012	1.446CysAsn: 1.446 ± 0.023	0.987CysPro: 0.987 ± 0.015	0.972CysGln: 0.972 ± 0.015	1.197CysArg: 1.197 ± 0.014	2.134CysSer: 2.134 ± 0.021	1.098CysThr: 1.098 ± 0.015	1.438CysVal: 1.438 ± 0.019	0.266CysTrp: 0.266 ± 0.007	0.815CysTyr: 0.815 ± 0.012	0.0CysXaa: 0.0 ± 0.0
Asp	2.838AspAla: 2.838 ± 0.018	1.206AspCys: 1.206 ± 0.014	7.477AspAsp: 7.477 ± 0.094	4.581AspGlu: 4.581 ± 0.038	2.324AspPhe: 2.324 ± 0.018	3.884AspGly: 3.884 ± 0.03	1.277AspHis: 1.277 ± 0.013	3.325AspIle: 3.325 ± 0.022	3.488AspLys: 3.488 ± 0.024	4.575AspLeu: 4.575 ± 0.026	1.113AspMet: 1.113 ± 0.011	3.943AspAsn: 3.943 ± 0.034	1.915AspPro: 1.915 ± 0.017	1.785AspGln: 1.785 ± 0.015	2.451AspArg: 2.451 ± 0.02	4.088AspSer: 4.088 ± 0.026	2.158AspThr: 2.158 ± 0.016	4.464AspVal: 4.464 ± 0.028	0.6AspTrp: 0.6 ± 0.009	1.936AspTyr: 1.936 ± 0.018	0.0AspXaa: 0.0 ± 0.0
Glu	2.927GluAla: 2.927 ± 0.023	1.241GluCys: 1.241 ± 0.017	3.659GluAsp: 3.659 ± 0.027	4.623GluGlu: 4.623 ± 0.041	2.224GluPhe: 2.224 ± 0.019	2.308GluGly: 2.308 ± 0.019	1.244GluHis: 1.244 ± 0.013	3.601GluIle: 3.601 ± 0.024	4.939GluLys: 4.939 ± 0.035	4.9GluLeu: 4.9 ± 0.035	1.652GluMet: 1.652 ± 0.017	3.819GluAsn: 3.819 ± 0.026	1.645GluPro: 1.645 ± 0.019	2.15GluGln: 2.15 ± 0.02	2.888GluArg: 2.888 ± 0.021	3.92GluSer: 3.92 ± 0.022	3.014GluThr: 3.014 ± 0.023	3.403GluVal: 3.403 ± 0.024	0.548GluTrp: 0.548 ± 0.01	1.643GluTyr: 1.643 ± 0.014	0.0GluXaa: 0.0 ± 0.0
Phe	2.063PheAla: 2.063 ± 0.014	1.063PheCys: 1.063 ± 0.014	2.505PheAsp: 2.505 ± 0.015	2.364PheGlu: 2.364 ± 0.019	2.114PhePhe: 2.114 ± 0.021	2.192PheGly: 2.192 ± 0.02	1.099PheHis: 1.099 ± 0.012	2.793PheIle: 2.793 ± 0.023	2.961PheLys: 2.961 ± 0.019	3.962PheLeu: 3.962 ± 0.023	0.977PheMet: 0.977 ± 0.011	2.829PheAsn: 2.829 ± 0.019	1.564PhePro: 1.564 ± 0.014	1.759PheGln: 1.759 ± 0.016	1.805PheArg: 1.805 ± 0.014	3.663PheSer: 3.663 ± 0.027	2.196PheThr: 2.196 ± 0.019	2.848PheVal: 2.848 ± 0.021	0.496PheTrp: 0.496 ± 0.008	1.597PheTyr: 1.597 ± 0.018	0.0PheXaa: 0.0 ± 0.0
Gly	2.472GlyAla: 2.472 ± 0.033	1.228GlyCys: 1.228 ± 0.015	3.107GlyAsp: 3.107 ± 0.028	2.552GlyGlu: 2.552 ± 0.023	2.165GlyPhe: 2.165 ± 0.026	3.742GlyGly: 3.742 ± 0.043	1.211GlyHis: 1.211 ± 0.014	2.572GlyIle: 2.572 ± 0.023	3.156GlyLys: 3.156 ± 0.024	4.082GlyLeu: 4.082 ± 0.034	1.143GlyMet: 1.143 ± 0.014	2.797GlyAsn: 2.797 ± 0.03	1.819GlyPro: 1.819 ± 0.048	1.835GlyGln: 1.835 ± 0.031	2.6GlyArg: 2.6 ± 0.022	4.329GlySer: 4.329 ± 0.043	2.427GlyThr: 2.427 ± 0.021	3.106GlyVal: 3.106 ± 0.022	0.584GlyTrp: 0.584 ± 0.011	1.746GlyTyr: 1.746 ± 0.021	0.0GlyXaa: 0.0 ± 0.0
His	1.098HisAla: 1.098 ± 0.014	0.626HisCys: 0.626 ± 0.011	1.234HisAsp: 1.234 ± 0.012	1.192HisGlu: 1.192 ± 0.012	1.16HisPhe: 1.16 ± 0.013	1.161HisGly: 1.161 ± 0.013	1.305HisHis: 1.305 ± 0.022	1.441HisIle: 1.441 ± 0.014	1.45HisLys: 1.45 ± 0.013	2.474HisLeu: 2.474 ± 0.018	0.528HisMet: 0.528 ± 0.008	1.585HisAsn: 1.585 ± 0.018	1.176HisPro: 1.176 ± 0.014	1.566HisGln: 1.566 ± 0.02	1.231HisArg: 1.231 ± 0.013	2.051HisSer: 2.051 ± 0.019	1.162HisThr: 1.162 ± 0.014	1.561HisVal: 1.561 ± 0.013	0.269HisTrp: 0.269 ± 0.006	0.888HisTyr: 0.888 ± 0.011	0.0HisXaa: 0.0 ± 0.0
Ile	2.836IleAla: 2.836 ± 0.02	1.501IleCys: 1.501 ± 0.014	3.328IleAsp: 3.328 ± 0.018	3.394IleGlu: 3.394 ± 0.021	2.912IlePhe: 2.912 ± 0.022	2.843IleGly: 2.843 ± 0.027	1.367IleHis: 1.367 ± 0.015	4.24IleIle: 4.24 ± 0.032	4.309IleLys: 4.309 ± 0.025	5.134IleLeu: 5.134 ± 0.027	1.328IleMet: 1.328 ± 0.012	5.057IleAsn: 5.057 ± 0.048	2.391IlePro: 2.391 ± 0.021	2.106IleGln: 2.106 ± 0.017	2.561IleArg: 2.561 ± 0.017	5.241IleSer: 5.241 ± 0.028	3.315IleThr: 3.315 ± 0.02	3.608IleVal: 3.608 ± 0.024	0.566IleTrp: 0.566 ± 0.007	1.973IleTyr: 1.973 ± 0.018	0.0IleXaa: 0.0 ± 0.0
Lys	2.956LysAla: 2.956 ± 0.02	1.651LysCys: 1.651 ± 0.019	3.58LysAsp: 3.58 ± 0.023	4.344LysGlu: 4.344 ± 0.03	3.015LysPhe: 3.015 ± 0.018	2.478LysGly: 2.478 ± 0.027	1.831LysHis: 1.831 ± 0.016	4.682LysIle: 4.682 ± 0.029	6.647LysLys: 6.647 ± 0.052	6.69LysLeu: 6.69 ± 0.035	2.049LysMet: 2.049 ± 0.018	5.377LysAsn: 5.377 ± 0.031	2.66LysPro: 2.66 ± 0.024	3.03LysGln: 3.03 ± 0.022	3.646LysArg: 3.646 ± 0.023	5.75LysSer: 5.75 ± 0.04	3.955LysThr: 3.955 ± 0.026	3.828LysVal: 3.828 ± 0.025	0.714LysTrp: 0.714 ± 0.01	2.402LysTyr: 2.402 ± 0.018	0.0LysXaa: 0.0 ± 0.0
Leu	4.886LeuAla: 4.886 ± 0.03	1.893LeuCys: 1.893 ± 0.016	4.462LeuAsp: 4.462 ± 0.024	5.044LeuGlu: 5.044 ± 0.034	3.793LeuPhe: 3.793 ± 0.027	3.629LeuGly: 3.629 ± 0.024	2.252LeuHis: 2.252 ± 0.018	5.001LeuIle: 5.001 ± 0.027	7.231LeuLys: 7.231 ± 0.038	8.614LeuLeu: 8.614 ± 0.051	2.194LeuMet: 2.194 ± 0.016	5.467LeuAsn: 5.467 ± 0.027	4.11LeuPro: 4.11 ± 0.027	4.166LeuGln: 4.166 ± 0.032	3.956LeuArg: 3.956 ± 0.024	7.341LeuSer: 7.341 ± 0.036	5.232LeuThr: 5.232 ± 0.031	4.97LeuVal: 4.97 ± 0.028	0.859LeuTrp: 0.859 ± 0.011	2.601LeuTyr: 2.601 ± 0.021	0.0LeuXaa: 0.0 ± 0.0
Met	1.573MetAla: 1.573 ± 0.015	0.501MetCys: 0.501 ± 0.01	1.201MetAsp: 1.201 ± 0.013	1.464MetGlu: 1.464 ± 0.013	1.039MetPhe: 1.039 ± 0.011	0.948MetGly: 0.948 ± 0.013	0.518MetHis: 0.518 ± 0.008	1.288MetIle: 1.288 ± 0.012	2.117MetLys: 2.117 ± 0.019	2.117MetLeu: 2.117 ± 0.02	0.859MetMet: 0.859 ± 0.014	1.505MetAsn: 1.505 ± 0.015	0.873MetPro: 0.873 ± 0.011	0.888MetGln: 0.888 ± 0.011	1.034MetArg: 1.034 ± 0.012	1.909MetSer: 1.909 ± 0.014	1.432MetThr: 1.432 ± 0.014	1.334MetVal: 1.334 ± 0.014	0.261MetTrp: 0.261 ± 0.006	0.731MetTyr: 0.731 ± 0.013	0.0MetXaa: 0.0 ± 0.0
Asn	2.933AsnAla: 2.933 ± 0.021	1.451AsnCys: 1.451 ± 0.021	4.803AsnAsp: 4.803 ± 0.041	3.678AsnGlu: 3.678 ± 0.023	3.078AsnPhe: 3.078 ± 0.023	3.058AsnGly: 3.058 ± 0.024	1.632AsnHis: 1.632 ± 0.019	5.4AsnIle: 5.4 ± 0.045	5.138AsnLys: 5.138 ± 0.033	5.269AsnLeu: 5.269 ± 0.028	1.385AsnMet: 1.385 ± 0.013	13.919AsnAsn: 13.919 ± 0.225	2.108AsnPro: 2.108 ± 0.02	2.275AsnGln: 2.275 ± 0.019	2.597AsnArg: 2.597 ± 0.021	6.031AsnSer: 6.031 ± 0.044	3.122AsnThr: 3.122 ± 0.028	4.283AsnVal: 4.283 ± 0.033	0.549AsnTrp: 0.549 ± 0.009	2.455AsnTyr: 2.455 ± 0.02	0.0AsnXaa: 0.0 ± 0.0
Pro	2.215ProAla: 2.215 ± 0.021	0.812ProCys: 0.812 ± 0.018	2.111ProAsp: 2.111 ± 0.02	2.038ProGlu: 2.038 ± 0.018	1.555ProPhe: 1.555 ± 0.015	2.214ProGly: 2.214 ± 0.061	1.037ProHis: 1.037 ± 0.013	2.203ProIle: 2.203 ± 0.019	2.314ProLys: 2.314 ± 0.019	3.213ProLeu: 3.213 ± 0.023	0.812ProMet: 0.812 ± 0.01	2.265ProAsn: 2.265 ± 0.02	2.712ProPro: 2.712 ± 0.034	1.891ProGln: 1.891 ± 0.024	1.576ProArg: 1.576 ± 0.015	3.939ProSer: 3.939 ± 0.026	2.73ProThr: 2.73 ± 0.019	2.314ProVal: 2.314 ± 0.022	0.382ProTrp: 0.382 ± 0.007	1.244ProTyr: 1.244 ± 0.012	0.0ProXaa: 0.0 ± 0.0
Gln	1.866GlnAla: 1.866 ± 0.018	0.877GlnCys: 0.877 ± 0.018	1.517GlnAsp: 1.517 ± 0.014	1.967GlnGlu: 1.967 ± 0.018	1.509GlnPhe: 1.509 ± 0.014	1.438GlnGly: 1.438 ± 0.028	1.727GlnHis: 1.727 ± 0.023	2.265GlnIle: 2.265 ± 0.018	2.779GlnLys: 2.779 ± 0.022	4.285GlnLeu: 4.285 ± 0.036	1.075GlnMet: 1.075 ± 0.012	2.333GlnAsn: 2.333 ± 0.019	2.159GlnPro: 2.159 ± 0.027	6.464GlnGln: 6.464 ± 0.112	1.944GlnArg: 1.944 ± 0.018	3.024GlnSer: 3.024 ± 0.021	2.271GlnThr: 2.271 ± 0.017	1.902GlnVal: 1.902 ± 0.015	0.39GlnTrp: 0.39 ± 0.007	1.121GlnTyr: 1.121 ± 0.014	0.0GlnXaa: 0.0 ± 0.0
Arg	2.033ArgAla: 2.033 ± 0.018	1.146ArgCys: 1.146 ± 0.015	2.362ArgAsp: 2.362 ± 0.019	2.557ArgGlu: 2.557 ± 0.021	1.848ArgPhe: 1.848 ± 0.016	2.108ArgGly: 2.108 ± 0.025	1.338ArgHis: 1.338 ± 0.012	2.542ArgIle: 2.542 ± 0.019	3.72ArgLys: 3.72 ± 0.02	4.134ArgLeu: 4.134 ± 0.023	1.215ArgMet: 1.215 ± 0.012	2.905ArgAsn: 2.905 ± 0.02	1.858ArgPro: 1.858 ± 0.018	2.016ArgGln: 2.016 ± 0.021	2.965ArgArg: 2.965 ± 0.024	3.762ArgSer: 3.762 ± 0.025	2.287ArgThr: 2.287 ± 0.019	2.447ArgVal: 2.447 ± 0.02	0.559ArgTrp: 0.559 ± 0.008	1.553ArgTyr: 1.553 ± 0.014	0.0ArgXaa: 0.0 ± 0.0
Ser	4.467SerAla: 4.467 ± 0.027	1.99SerCys: 1.99 ± 0.021	4.722SerAsp: 4.722 ± 0.026	4.124SerGlu: 4.124 ± 0.028	3.721SerPhe: 3.721 ± 0.024	4.429SerGly: 4.429 ± 0.034	1.978SerHis: 1.978 ± 0.016	4.673SerIle: 4.673 ± 0.028	5.705SerLys: 5.705 ± 0.034	7.645SerLeu: 7.645 ± 0.038	1.841SerMet: 1.841 ± 0.017	6.517SerAsn: 6.517 ± 0.044	3.549SerPro: 3.549 ± 0.032	3.05SerGln: 3.05 ± 0.024	3.738SerArg: 3.738 ± 0.029	12.414SerSer: 12.414 ± 0.12	5.687SerThr: 5.687 ± 0.039	4.629SerVal: 4.629 ± 0.027	0.8SerTrp: 0.8 ± 0.01	2.612SerTyr: 2.612 ± 0.021	0.0SerXaa: 0.0 ± 0.0
Thr	3.601ThrAla: 3.601 ± 0.027	1.375ThrCys: 1.375 ± 0.018	2.829ThrAsp: 2.829 ± 0.018	2.676ThrGlu: 2.676 ± 0.022	2.565ThrPhe: 2.565 ± 0.02	2.812ThrGly: 2.812 ± 0.063	1.163ThrHis: 1.163 ± 0.014	3.325ThrIle: 3.325 ± 0.021	3.578ThrLys: 3.578 ± 0.028	4.744ThrLeu: 4.744 ± 0.03	1.187ThrMet: 1.187 ± 0.013	3.957ThrAsn: 3.957 ± 0.03	2.467ThrPro: 2.467 ± 0.022	1.686ThrGln: 1.686 ± 0.014	2.141ThrArg: 2.141 ± 0.019	6.099ThrSer: 6.099 ± 0.042	5.919ThrThr: 5.919 ± 0.066	3.119ThrVal: 3.119 ± 0.02	0.583ThrTrp: 0.583 ± 0.009	1.644ThrTyr: 1.644 ± 0.018	0.0ThrXaa: 0.0 ± 0.0
Val	3.632ValAla: 3.632 ± 0.023	1.704ValCys: 1.704 ± 0.025	3.774ValAsp: 3.774 ± 0.025	3.628ValGlu: 3.628 ± 0.022	2.453ValPhe: 2.453 ± 0.02	3.245ValGly: 3.245 ± 0.03	1.385ValHis: 1.385 ± 0.014	3.712ValIle: 3.712 ± 0.023	4.02ValLys: 4.02 ± 0.027	5.105ValLeu: 5.105 ± 0.027	1.425ValMet: 1.425 ± 0.012	3.532ValAsn: 3.532 ± 0.025	2.201ValPro: 2.201 ± 0.019	2.11ValGln: 2.11 ± 0.018	2.674ValArg: 2.674 ± 0.019	4.557ValSer: 4.557 ± 0.026	3.536ValThr: 3.536 ± 0.024	4.393ValVal: 4.393 ± 0.029	0.63ValTrp: 0.63 ± 0.009	1.86ValTyr: 1.86 ± 0.017	0.0ValXaa: 0.0 ± 0.0
Trp	0.414TrpAla: 0.414 ± 0.008	0.227TrpCys: 0.227 ± 0.006	0.508TrpAsp: 0.508 ± 0.009	0.434TrpGlu: 0.434 ± 0.008	0.526TrpPhe: 0.526 ± 0.009	0.409TrpGly: 0.409 ± 0.008	0.242TrpHis: 0.242 ± 0.005	0.622TrpIle: 0.622 ± 0.009	0.8TrpLys: 0.8 ± 0.01	1.084TrpLeu: 1.084 ± 0.014	0.351TrpMet: 0.351 ± 0.006	0.634TrpAsn: 0.634 ± 0.01	0.353TrpPro: 0.353 ± 0.006	0.363TrpGln: 0.363 ± 0.008	0.551TrpArg: 0.551 ± 0.01	0.899TrpSer: 0.899 ± 0.015	0.569TrpThr: 0.569 ± 0.009	0.545TrpVal: 0.545 ± 0.009	0.164TrpTrp: 0.164 ± 0.005	0.342TrpTyr: 0.342 ± 0.007	0.0TrpXaa: 0.0 ± 0.0
Tyr	1.473TyrAla: 1.473 ± 0.014	0.809TyrCys: 0.809 ± 0.011	1.984TyrAsp: 1.984 ± 0.019	1.771TyrGlu: 1.771 ± 0.016	1.668TyrPhe: 1.668 ± 0.016	1.642TyrGly: 1.642 ± 0.015	0.87TyrHis: 0.87 ± 0.01	1.99TyrIle: 1.99 ± 0.019	2.188TyrLys: 2.188 ± 0.017	2.968TyrLeu: 2.968 ± 0.023	0.746TyrMet: 0.746 ± 0.009	2.313TyrAsn: 2.313 ± 0.023	1.204TyrPro: 1.204 ± 0.013	1.252TyrGln: 1.252 ± 0.015	1.532TyrArg: 1.532 ± 0.016	2.48TyrSer: 2.48 ± 0.02	1.518TyrThr: 1.518 ± 0.014	1.932TyrVal: 1.932 ± 0.02	0.326TyrTrp: 0.326 ± 0.007	1.281TyrTyr: 1.281 ± 0.016	0.0TyrXaa: 0.0 ± 0.0
Xaa	0.0XaaAla: 0.0 ± 0.0	0.0XaaCys: 0.0 ± 0.0	0.0XaaAsp: 0.0 ± 0.0	0.0XaaGlu: 0.0 ± 0.0	0.0XaaPhe: 0.0 ± 0.0	0.0XaaGly: 0.0 ± 0.0	0.0XaaHis: 0.0 ± 0.0	0.0XaaIle: 0.0 ± 0.0	0.0XaaLys: 0.0 ± 0.0	0.0XaaLeu: 0.0 ± 0.0	0.0XaaMet: 0.0 ± 0.0	0.001XaaAsn: 0.001 ± 0.0	0.0XaaPro: 0.0 ± 0.0	0.0XaaGln: 0.0 ± 0.0	0.0XaaArg: 0.0 ± 0.0	0.0XaaSer: 0.0 ± 0.0	0.0XaaThr: 0.0 ± 0.0	0.0XaaVal: 0.0 ± 0.0	0.0XaaTrp: 0.0 ± 0.0	0.0XaaTyr: 0.0 ± 0.0	0.008XaaXaa: 0.008 ± 0.005

Statistics based on 23328 proteins (8768599 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

---