Table S1.

List of expression constructs with test expression results

Construct	Gene(s)	Vector	Affinity tag	Tag position	Expression
pCB98	43	pCDF1b	—	—	Insoluble
pCB40	44	pCDF1b	His6	N-terminal	Soluble
pCB94	46	pAD100	—	—	No
pCB101	46	pCDF1b	—	—	Insoluble
pCB6	47	pET32b*	Trx-His6-TEV	N-terminal	Soluble
pCB68	47	pCDF1b	—	—	Soluble
pCB15	48	pAD100	FLAG-His6	C-terminal	No
pCB44	48	p15TV-L	His6-TEV	N-terminal	Insoluble
pCB108	48	pCDF1b	—	—	No, reduced culture growth
pCB119	43–44	pCDF1b	—	—	Soluble, Mup43, -44
pCB82	43–44–45–46–47–48	pAD100	FLAG-His6	C-terminal	Soluble, Mup43, -44, -46, -47, -48; 45†
pCB83	44–45–46–47–48	pAD100	FLAG-His6	C-terminal	Soluble, Mup44, -46, -47, -48
pCB85	46–47–48	pAD100	FLAG-His6	C-terminal	Soluble, Mup46, -47, -48
pCB111	46–47–48	p15TV-L	His6-TEV	N-terminal	Soluble, Mup46, -47, -48
pCB14	47–48	pAD100	FLAG-His6	C-terminal	Soluble, Mup47, -48
pCB63	47–48	pET32b*	Trx-His6-TEV	N-terminal	Soluble, Mup47, -48
pCB100	43–44–46–47–48	pCB85‡	FLAG-His6	C-terminal	Soluble, Mup43, -44, -46, -47, -48
pCB105	43–44–45–46–47–48–49–50	p15TV-L	His6-TEV	N-terminal	Soluble, Mup43, -44, -46, -47, -48, -49 ,-50
pCB127	43–44–45–46–47–48–49–50	pAD100	His6	N-terminal	Soluble, Mup43, -44, -46, -47, -48, -49, -50

Vector backbones pCDF1b and pET21d (EMD Millipore), pAD100 (33), p15TV-L (Clinical Genomics Centre, University Health Network, Toronto, ON, Canada). Tagged ORF in multicistronic constructs are underlined. His6, hexahistidine tag; Trx, thioredoxin tag.

^*Modified expression vector pET32b (Novagen), enterokinase protease cleavage site replaced with tobacco virus etch (TEV) protease site.

^†Detected upon cross-linking.

^‡Cloned into 5′ NcoI site, introducing a 3′ ribosome binding site.