slow SQL query

Could you please tell why this simple postgreSQL query takes over 10 min to give result?

select distinct protein_info_table.com_id, annotator, common_name, synonyms
from protein_info_table, protein_feature_table
where
(protein_info_table.sim_id = protein_feature_table.sim_id and protein_feature_table.scaffold ilike '%Scaffoldi3148%') or protein_info_table.com_id ilike '%013015%';

The two table's structures are:

1. protein_info_table
sim_id | character varying(100) | not null default 'none'::character varying
com_id | character varying(100) | not null
annotator | character varying(200) | not null default 'none'::character varying
model | character varying(50) | not null default 'none'::character varying
evidence | character varying(50) | not null default 'none'::character varying
family | text | not null default 'none'::text
common_name | character varying(100) | not null default 'none'::text
synonyms | text | not null default 'none'::text

2. protein_feature_table
scaffold | character varying(50) | not null default 'none'::character varying
source | character varying(50) | not null default 'none'::character varying
feature | character varying(50) | not null default 'none'::character varying
gene_start | integer | not null default -1
gene_end | integer | not null default -1
score | character varying(50) | not null default 'none'::character varying

Here is the EXPLAIN ANALYSIS result:
-------------------------------------------------------------------------
Unique (cost=679701663.74..679765485.18 rows=126661 width=886)
-> Sort (cost=679701663.74..679714428.03 rows=5105715 width=886)
Sort Key: protein_info_table.com_id, protein_info_table.annotator, protein_info_table.common_name, protein_info_table.synonyms
-> Nested Loop (cost=0.00..664867718.11 rows=5105715 width=886)
Join Filter: (((("outer".sim_id)::text = ("inner".sim_id)::text) AND (("inner".scaffold)::text ~~* '%Scaffoldi3148%'::text)) OR (("outer".com_id)::text ~~* '%013015%'::text))
-> Seq Scan on protein_info_table (cost=0.00..5446.61 rows=126661 width=1104)
-> Seq Scan on protein_feature_table (cost=0.00..3044.69 rows=125969 width=336)
(7 rows)

Thank you for any advice.
Qiul